# pooja.mahesha

aneesh.kg posted a new topic called Quantitative Section - Online Tutoring in the GMAT Strategy forum
“Hello, I am an online GMAT tutor with over 3 years of experience and have taught over 300 students for the GMAT. I handle only the Quantitative Section. I''ve been quite active on this community and you can read my posts to get a better idea about my teaching skills. I''m planning to enrol a ...”
June 13, 2014
aneesh.kg posted a reply to gmat prep number properties in the Data Sufficiency forum
“Hi p111, Your basics are absolutely fine. You raise a very valid point and I agree with you. The question must mention that x, y, z are non-zero. For e.g., x = y = z = 0 is a possible solution from Statement (1). This is not an official question and clearly, the person who made this didn''t ...”
July 5, 2013
aneesh.kg posted a reply to OG QR 2nd Ed. DS #124 in the Data Sufficiency forum
“Hi p111, You''re right. It''s wrong to generalise it. Your solution is also correct. However, here''s how I would do it and I think it''s more elegant. Statement(1): r + s = 4rs Dividing both the sides of the equation by rs. (We can do this ONLY BECAUSE rs is not 0) (r + s) / rs = 4rs / ...”
July 5, 2013
aneesh.kg posted a reply to Study Group in Pune in the GMAT Strategy forum
“Hello GMAT Aspirants, My name is Aneesh, and I''m a IIT Madras Alumnus. I''ve been helping people for GMAT over the past 19 months and must''ve helped over 200 GMAT students till date. (I handle the QA section). I am also heavily active on BeatTheGMAT with ~380 posts and have a youtube channel ...”
May 16, 2013
aneesh.kg posted a reply to Absolute DS in the Data Sufficiency forum
“|X| is always a positive number. If X is positive, |X| = X, but if X is negative, |X| = -X. And Yes, |0| = 0. Statement 1: X = A - B If A - B is a positive number then its modulus, i.e. |X| = |A - B| = A - B, but if A - B is a negative number then |X| = |A - B| = B - A. INSUFFICIENT, because ...”
March 22, 2013
Anurag@Gurome posted a reply to GMAT PREP PS question in the Problem Solving forum
“Because the question said "... the store packs the notepads in packages that contain either 3 notepads of the same size and the same color or 3 notepads of the same size and of 3 different colors" Those are two different scenarios. For each of them, 8 different packages are possible. ...”
March 13, 2013
Anurag@Gurome posted a reply to Word Problem - Ages question in the Problem Solving forum
“These are not two approaches, these are calculating the maximum age of the child Jane could have baby-sit at two different points in the time, i.e. when she started baby-sitting and stopped it. Obviously the greater of the two will be the potential correct answer. A proper mathematical ...”
March 8, 2013
Anurag@Gurome posted a reply to how to solve absolute values and absolute value inequalities in the GMAT Math forum
“You''re not doing anything wrong except that redundancy part. But before remembering this hard and fast "rules" and "shortcuts", I''ll suggest you to tackle these problems logically. Once you practice to do so there won''t be any rules to remember. The practical implication ...”
March 8, 2013
Anurag@Gurome posted a reply to Arithmetic Properties of Number in the Data Sufficiency forum
“I''m assuming this is the problem you are talking about... Statement 1: As v and z can have values either 1 or 2 or 3, for (v + z) to be equal to 6, v and z both must be equal to 3. Now, as v is present second row and second column, no other member of second row and second column can have ...”
March 8, 2013
Anurag@Gurome posted a reply to how to solve absolute values and absolute value inequalities in the GMAT Math forum
“That''s what you already did in 2.a. 2.a ---> (y + 14) = -2 <---- Multiply both sides by -1 --> -y - 14 = 2 <--- 2.b 2.b is completely redundant as it is a different version of 2.a By definition of |x|, |x| = x if x ≥ 0 and |x| = -x if x < 0 Hence, here if (y + 14) ≥ 0, ...”
March 8, 2013
Anurag@Gurome posted a reply to Real Numbers - Arithematic in the Problem Solving forum
“The expression will not be real only if the expression under root is negative. So, (-2(x+1) - (x-2)) < 0 --> 2(x + 1) + (x - 2) > 0 --> 3x > 0 --> x > 0 Only possible answer is x = 0.5 The correct answer is E.”
March 8, 2013
Anurag@Gurome posted a reply to Evenly Divisible ?? in the Data Sufficiency forum
“In simple words, "evenly divisible" means ''divisible''. Statement 1: 2R is divisible by 3. As 2 is not a multiple of 3, R must be a multiple of 3. Sufficient Statement 2: 3R is divisible by 3. As 3 is a multiple of 3, R may or may not be a multiple of 3. Not sufficient ...”
March 8, 2013
Anurag@Gurome posted a reply to optimization in the Problem Solving forum
“No. The reverse is not true. To illustrate with a simple example, take xy = 4 ---> (4 + 1) > (2 + 2)”
March 7, 2013
Anurag@Gurome posted a reply to optimization in the Problem Solving forum
“Algebraic Method: (x + y)² = (x² + y² + 2xy) = (100 + 2xy) ---> (x + y) = √(100 + 2xy) To maximize (x + y), we need to maximize xy which we will do by maximizing x²y². Now, remember this rule if you don''t know it yet, Given the sum of two numbers, their product will be maximum when ...”
March 7, 2013
Anurag@Gurome posted a reply to optimization in the Problem Solving forum
“x² + y² = 100 Hence, 0 ≤ x ≤ 10 and 0≤ y ≤ 10 Some obvious possible values for x and y are {x = 10, y = 0} or {x = 6, y = 8} In first case, (x + y) = 10 ---> Discard option 1 In second case, (x + y) = 14 ---> Discard option 2 Now, 7² = 49 ---> 7² + 7² = 98 is just less ...”
March 7, 2013
Anurag@Gurome posted a reply to Population Ratio in the Data Sufficiency forum
“Let us take an example question like "The population of a town is 6,250,000. If the ratio of number of males to number of females in the town is 14:11, how many male are there in the town? Also, what percentage of the population are female?" Ratio of male to female is 14:11 Hence, in ...”
March 7, 2013
Anurag@Gurome posted a reply to Population Ratio in the Data Sufficiency forum
“I''m afraid you don''t remember the numbers properly. Because the total population (6,754,000) is not a multiple of (14 + 9) = 23. Hence, the number of males and females will not be integer which is impossible.”
March 7, 2013
Anurag@Gurome posted a reply to Remainders in the Problem Solving forum
“No, that is correct. But the question asks "...which of the following could NOT be a possible value of M + N?" And as Mitch has shown, (M + N) will be 4 more than a multiple of 6. Hence, the correct option should NOT yield a multiple of 6 when 4 is subtracted from it. As 10 yields a ...”
March 7, 2013
Anurag@Gurome posted a reply to Factors of 24 in the Problem Solving forum
“The possible values of x and y are : 1, 2, 3, 4, 6, 8, 12, and 24 also x ≠ y Option I This is a perfect square. The only factors of 24 that are perfect squares are 1 and 4. If (x + y)² is equal to 1 or 4, then (x + y) = 1 or (x + y) = 2 There is no way, x and y can have values from the ...”
March 7, 2013
Anurag@Gurome posted a reply to Gmat question help! in the Problem Solving forum
“Thank you for pointing out that we can approximate the actual answer to select the best answer. I''ve modified my reply accordingly. However, I believe in GMAT if you come across such a question they will either include the exact answer in the options or ask to find out the approximate ratio. ...”
March 7, 2013
Anurag@Gurome posted a reply to Double set matrix problem in the Problem Solving forum
“Here is a method that someone will find easier than the matrix method. Let us assume there are 100 students in the school. Hence, 60 of them love roller coasters. Now, (100 - 20)% = 80% of these 60 students do not own chinchillas. 80% of 60 = 80*60/100 = 48 Hence, 48% of students love ...”
March 7, 2013
Anurag@Gurome posted a reply to Double set matrix problem in the Problem Solving forum
“Yes, it is 80% of 60, i.e. 80% of the students who love roller coasters. But the question asks you to find out the same in terms of total students which is 48%. Hope that helps.”
March 7, 2013
Anurag@Gurome posted a reply to Gmat question help (part two) in the Problem Solving forum
“These questions are not very much clear to me. In fact I feel the data provided is not complete because they can be interpreted in different ways. For example, in the first question it is mentioned that "... the trends for year 1 to year 2 continue to year 3...", which type of trend we ...”
March 7, 2013
Anurag@Gurome posted a reply to Algebra in the Problem Solving forum
“Let us assume n = 100 Hence, there is 40 ounce of vermouth and 60 ounce of gin. We have to make the ratio of vermouth to gin 25:75 by adding say x ounce of gin. So, 40/(60 + x) = 25/75 = 1/3 --> 60 + x = 3*40 = 120 --> x = 120 - 60 = 60 = (60/100)*100 = (3/5)*100 = (3/5)*n The ...”
March 7, 2013
Anurag@Gurome posted a reply to Gmat question help! in the Problem Solving forum
“Question Number 18: Let us assume, the sales for single glazing and double glazing in December of previous year was S and D, respectively. Hence, sales of single glazing in January = S - 20% of S =(0.80)*S = 40,000 ---> S = 40,000/0.8 And, sales of double glazing in January = D + 40% of D ...”
March 6, 2013
Anurag@Gurome posted a reply to Gmat question help! in the Problem Solving forum
“Question Number 17: Refer to the following table for the total sales in January, February, and April. http://s11.postimage.org/o69i52hr7/btg.jpg Hence, required ratio = (285 + 290)/230 = 575/230 = 5/2 The correct answer is E.”
March 6, 2013
Anurag@Gurome posted a reply to Gmat question help! in the Problem Solving forum
“Question Number 16: If the sales for the month of June follows the same trend as for April to May, the sales of single glazing, triple glazing, and wood embedded will increase by 5000 and the sales for double glazing and UPVC glazing will decrease by 10000. Hence, the difference in total sales ...”
March 6, 2013
Anurag@Gurome posted a reply to DS-Co-ordinate Geometry in the Data Sufficiency forum
“Refer to the post here >> http://www.beatthegmat.com/og-13-ds-q-129-t117128.html#491613”
March 6, 2013
Anurag@Gurome posted a reply to Reminders in the Problem Solving forum
“A/B = 4.35 ---> A = (4.35)*B = 4B + (0.35)*B Hence, when A is divided by B, the remainder is (0.35)*B = 35B/100 = 7B/20 = 7*(B/20) Hence, the remainder must be a multiple of 7. The correct answer is B.”
March 6, 2013
Anurag@Gurome posted a reply to probability in the Problem Solving forum
“I guess this is a DS problem posted in wrong forum. Anyway, the required probability = (Number of refined numbers in first 1000 positive integers)/1000 Hence, we need to know what is refined number and how many of them are in the first 1000 positive integers. Statement 1: This is not a ...”
March 6, 2013
Anurag@Gurome posted a reply to ALEBRA in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/gmat-ques-pls-help-t104479.html#449216”
March 6, 2013
Anurag@Gurome posted a reply to Remainders in the Problem Solving forum
“Are you trying to say 10 is multiple of 6?”
March 6, 2013
Anurag@Gurome posted a reply to OG - Q.137 in the Problem Solving forum
“As stated by Abhishek this equation is good enough for those who are fairly good at algebra. If someone feels it is a bit difficult to factorize the expression, here is a trick... --> (x² + 4x - 672) = 0 --> (x² + 4x + 4) - 676 = 0 --> (x + 2)² = 676 = 26² --> (x + 2) = ±26 ...”
March 6, 2013
Anurag@Gurome posted a reply to integrated reasoning question in the Problem Solving forum
“Because 3 is exactly 50% of 6.”
March 6, 2013
Anurag@Gurome posted a reply to What is value of x? in the Problem Solving forum
“Refer the following posts... http://www.beatthegmat.com/2-x-2-x-2-3-2-13-what-is-x-t178975.html#577790 http://www.beatthegmat.com/2-x-2-x-2-3-2-13-what-is-x-t178975.html#577789”
March 6, 2013
Anurag@Gurome posted a reply to Divisibility Quant Review (#169) in the Problem Solving forum
“Picking Number Approach: Least possible value of n² such that n² is divisible by 72 is 72*2 = 144 Hence, minimum possible value of n = 12. Largest possible integer that divides n is 12. Algebraic Approach: n² is divisible by 72 Hence we can write n² as 72k, where k is an positive ...”
March 6, 2013
Anurag@Gurome posted a reply to Quant Review- Divisibility in the Problem Solving forum
“n = 5*a + 1. n = 7*b + 3. Here, a and b are integers. Note that the difference between divider and remainder (5 - 1 and 7 - 3) is 4 in both the case. So add 4 on both sides of each of the 2 equations. So, we get n + 4 = 5*a + 5 = 5*(a + 1). n+4 = 7*b + 7 = 7*(b + 1). This means n+4 is a ...”
March 6, 2013
Anurag@Gurome posted a reply to OG - Q.137 in the Problem Solving forum
“Algebraic Approach: Let us assume that the regular hourly rate = R, and the estimated time = T Then RT = 336 ... Equation (1) Also, (R - 2)(T + 4) = 336 ... Equation (2) From Equations (1) and (2), RT = (R - 2)(T + 4) Solving we get, RT = RT - 2T + 4R - 8 T = 2R - 4 Now we can plug in ...”
March 6, 2013
Anurag@Gurome posted a reply to Probability problem in the Problem Solving forum
“Probability of missing at least one test = Probability of missing test in only one day + Probability of missing test on both the day Probability of missing test in only one day = (Probability of happening test on one of the day he was absent)*(Probability of not happening test on the other day he ...”
March 5, 2013
Anurag@Gurome posted a reply to Question on Algebra in Data Sufficiency in the Data Sufficiency forum
“Statement 1: Consider the following two cases, x = 0.5 ---> Statement 2: Consider the following two cases, x = -0.5 ---> 1 & 2 Together: Now, we know that x is greater than -1 but less than 0. Hence, the least integer greater than or equal to x will always be equal to 0. Sufficient ...”
March 5, 2013
Anurag@Gurome posted a reply to Bacteria Quadruples in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/problem3-t152589.html#543949”
March 5, 2013
Anurag@Gurome posted a reply to Basketball wins in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/problem9-t152956.html#544527”
March 5, 2013
Anurag@Gurome posted a reply to Time and work related in the Problem Solving forum
“The money will be distributed on the basis of how much they have contributed, i.e. what fraction of the work they have done NOT on the basis of their work efficiency, i.e. how much work they could''ve done. Hence, their daily wage will be (fraction of work they do in one day)*(total money) ...”
March 5, 2013
Anurag@Gurome posted a reply to Question regarding Manhattan Word Problems Book in the GMAT Math forum
“Selections and arrangements are different things. When you have to arrange something, first you have to select them. For example, say there are 5 people but 3 chairs. In how many ways the 5 people can sit on the 3 chairs? First we have to select 3 people from 5 people ---> Selection In ...”
March 5, 2013
Anurag@Gurome posted a reply to INTEGERS in the Problem Solving forum
“That doesn''t make any sense. Please check your source and post the actual question.”
March 5, 2013
Anurag@Gurome posted a reply to 343. Mark is playing poker at a casino. Mark starts playing in the Problem Solving forum
“Initially Mark had (0.2*140) = 28 chips of $100 and (140 - 28) = 112 chips of$20 Let us assume Mark placed N chips for the first bet. Hence, he placed N/10 chips of $100 for the first bet. Now, 30% of remaining chips = 3(140 - N)/10 chips are of$100. So, N/10 + 3(140 - N)/10 = 28 --> N + ...”
March 5, 2013
Anurag@Gurome posted a reply to probability question in the Problem Solving forum
“For each person who is both agent and clerk, we have two agents and one clerk. Hence, among (1 + 2 + 1) = 4 people there is only one person who is both agent and clerk. Required probability = 1/4 The correct answer is C.”
March 5, 2013
Anurag@Gurome posted a reply to Does xy=x2 (the 2 is the exponent) in the Data Sufficiency forum
“Statement 1: y² - xy = 0 ---> y(x - y) = 0 Now either y = 0 or x = y For y = 0, xy may not be equal to x² For x = y, xy is always equal to x² Not sufficient Statement 2: x² - 2xy + y² = 0 ---> (x - y)² = 0 ---> x = y Hence, xy is always equal to x² Sufficient The ...”
March 5, 2013
Anurag@Gurome posted a reply to Nova Book in the Problem Solving forum
“The method provided in the book is short and simple enough. You can try for 1 - C2 = 6 Number of ways to select 2 numbers from the set such that there sum is 5 --> {1 and 4} or {2 and 3} = 2 Hence, required probability = 2/6 = 1/3 The correct answer is B.”
March 4, 2013
Anurag@Gurome posted a reply to Is n-1>0? in the Data Sufficiency forum
“Statement 1: n² - n > 0 ---> n(n - 1) > 0 This means either n and (n - 1) are of same sign. Hence, it is possible that, Both are positive ---> (n - 1) > 0 Both are negative ---> (n - 1) < 0 Not sufficient Statement 2: n² = 9 --> n = ±3 Not sufficient 1 & ...”
March 4, 2013
Anurag@Gurome posted a reply to Unknown Digits in the Problem Solving forum
“Algebraic Solution: AB = (10A + B) CD = (10C + D) AAA = (100A + 10A + A) So, (10A + B) + (10C + D) = (100A + 10A + A) --> 10C + B + D = 100A + A --> C = The correct answer is D.”
March 4, 2013
Anurag@Gurome posted a reply to Unknown Digits in the Problem Solving forum
“Maximum possible value of the sum of 2 two-digit number is (99 + 99) = 198 In this case the sum is of the form AAA, i.e. a three-digit number whose all the three digits are same. Only possible sum is 111. This means A = 1 Now we can approach for finding C in two ways, Method #1 As A = 1, AB ...”
March 4, 2013
Anurag@Gurome posted a reply to Ratio or Not in the Problem Solving forum
“Plugging options: Note that the concentration (35%) of the final solution is closer to 40% solution than the 25% solution. Hence, amount of 25% solution in the final solution must be less than 1/2. This means C, D, or E cannot be the answer. Now, plug the options A and B. Option A: 25*(1/4) ...”
March 4, 2013
Anurag@Gurome posted a reply to Ratio or Not in the Problem Solving forum
“Algebraic Solution: Say, the fraction is x. Hence, x parts of the final solution is 25% solution and (1 - x) part is 40% solution. So, 25x + 40(1 - x) = 35 --> 15x = 40 - 35 = 5 --> x = 5/15 = 1/3 The correct answer is B.”
March 4, 2013
Anurag@Gurome posted a reply to Ugly Multiplication in the Problem Solving forum
“I can''t think of any easy way to do this except approximating the multiplications in each step as follows, 9/10 = 0.9 2 --> (0.9)*(0.9) = 0.81 3 --> (0.81)*(0.9) ≈ 0.73 4 --> (0.73)*(0.9) ≈ 0.65 5 --> (0.65)*(0.9) ≈ 0.59 6 --> (0.59)*(0.9) ≈ 0.53 7 --> ...”
March 4, 2013
Anurag@Gurome posted a reply to Probability 9 competitors in triathlon in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/probability-triplets-t112908.html#475030”
March 4, 2013
Anurag@Gurome posted a reply to OG DS-Algebra Question in the Data Sufficiency forum
“it is given that 2^2n. You cannot just change the base to -2. Statement 1: This means the product of two consecutive integers n and (n + 1) is 6. One obvious such pair is 2 and 3, i.e. n = 2. But -2, and -3, i.e. n = -3 is also another possibility. Not sufficient Statement 2: 16 can be ...”
March 4, 2013
Anurag@Gurome posted a reply to Grockit - Coordinate Geometry Q in the Data Sufficiency forum
“In coordinate geometry, reflection over or with respect to a line means as if there is a invisible mirror placed on the line. For example, in the following figure P'' is the reflection of P with respect to the line l, meaning as if there is an invisible mirror along the line l on which P'' is the ...”
March 4, 2013
Anurag@Gurome posted a reply to Mgmat CAT PS question in the Problem Solving forum
“Here is the explanation for official answer... Let assume the ages of Joan, Kylie, Lillian, and Miriam are J, K, L, and M, respectively. Hence, J = (K - 2), K = (L + 3), M = (J + 1) Expressing them all with respect to L only, K = (L + 3), J = (L + 1), and M = (L + 2) Hence, combined age of ...”
March 4, 2013
Anurag@Gurome posted a reply to Need help with this Manhattan Number properties guide Q in the Problem Solving forum
“Yes, you can do that. But that trick is helpful only when the number of times "the event doesn''t happen" is smaller than the number of times "the event happens". In this case, that trick will complicate your calculation as not choosing one white and one blue doesn''t mean ...”
March 4, 2013
Anurag@Gurome posted a reply to If 375y=x^2 and z and y are positive integers.... in the Problem Solving forum
“375 = 3*125 = 3*5*(5²) Hence, to make 375y a perfect square y must contain at least one 3 and one 5, i.e. y must be a multiple of 15. Hence, only 1 and 2 must be an integer. The correct answer is C. It is not necessary to find out the value of x. However, to clear your doubts, as I''ve ...”
March 4, 2013
Anurag@Gurome posted a reply to Mixture/ratio problem 4 in the Problem Solving forum
“In 14 liters of drink A, amount of milk = (4/7)*14 = 8 liter Let us assume that, we need to add x liters of fruit juice. Hence, total amount of drink = (14 + x) As we haven''t add any milk, amount of milk is 8 liter So, 8/(14 + x) = 3/7 --> 3(14 + x) = 56 --> 3x = 56 - 42 --> x = ...”
March 3, 2013
Anurag@Gurome posted a reply to AMixture/ratio problem 3 in the Problem Solving forum
“20% of the bottle = 70 ml Hence, 80% of the bottle = 4*70 ml Now, amount of guava juice in the bottle = 60% of 80% of the bottle = 60% of 4*70 ml = 60*4*70/100 = 6*4*7 = 168 The correct answer is B.”
March 3, 2013
Anurag@Gurome posted a reply to DS Percent of females in the Data Sufficiency forum
“As neither the question nor the statements tell us anything about the percentage of males, there is a chance that both statements together also will not be sufficient. Let us check that scenario first with some numbers. Example 1: P = F = I = 100 --> Total = 300 Total number of female = 40% ...”
March 3, 2013
Anurag@Gurome posted a reply to Question on Average salary in the Data Sufficiency forum
“Let us assume the annual salaries of Mary, Jim, and Kate are M, J, and K, respectively. Hence, M is greater than J and K. Hence, (M - J) = 2(M - K) ---> M + J = 2K Hence, average salary = (M + J + K)/3 = (2 K+ K)/3 = K Hence, we need to find K. Clearly, statement 2 is sufficient bu ...”
March 3, 2013
Anurag@Gurome posted a reply to Number line in the Data Sufficiency forum
“Statement 1: This means C is the midpoint of AB, AC = BC = 9 Hence, possible scenarios are... A--D---C-----B --> In this case BD = BC + CD = 9 + 8 = 17 A-----C---D--B --> In this case BD = BC - CD = 9 - 8 = 1 Not sufficient Statement 2: Not enough to conclude anything. Not ...”
March 3, 2013
Anurag@Gurome posted a reply to DS - Question in the Problem Solving forum
“.. is not an integer." because if √(10d) is an integer, then it is not possible for √d to be an integer which is contradictory to statement 1. I am replying assuming the correction. Otherwise, if the question is considered as posted, both statements will be sufficient to answer the ...”
March 3, 2013
Anurag@Gurome posted a reply to product of integers in the Data Sufficiency forum
“Product of first 8 positive integers = 1*2*3*4*5*6*7*8 = (2*4*2*8)*(3*3*5*7) = (2^7)*(3^2)*(5*7) As a and n are both positive integers greater than 1, only possible values for a and n are either {a = 2 and 2 ≤ n ≤ 7} or {a = 3 and n = 2} or {a = 4 and 2 ≤ n ≤ 3} or {a = 8 and n = 2} ...”
March 3, 2013
Anurag@Gurome posted a reply to Minimum possible population in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/question-from-gmat-prep-help-please-3-t110122.html#464522”
March 3, 2013
Anurag@Gurome posted a reply to Percentage population employed in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/idea-of-overlapping-sets-t112758.html#474556”
March 3, 2013
Anurag@Gurome posted a reply to Inequalities x, y, z in the Problem Solving forum
“The actual questions asks "... which of the following statements can be true?" Refer to the post here >> http://www.beatthegmat.com/if-x-y2-z4-t72017.html#326108”
March 3, 2013
Anurag@Gurome posted a reply to DS: Numbers in the Data Sufficiency forum
“Statement 1: Consider the following two lists... {0, 0, 0} ---> All numbers are equal to zero {0, 0, 1} ---> All numbers are not equal to zero Not sufficient Statement 2: Let us take a general case for three numbers a, b, and c. Hence, (a + b) = 0, (b + c) = 0, and (a + c) = 0 ...”
March 3, 2013
Anurag@Gurome posted a reply to Coffee cup temperature in the Problem Solving forum
“Temperature after t minutes = 120*The correct answer is B”
March 3, 2013
Anurag@Gurome posted a reply to Of 1400 college teachers surveyed in the Data Sufficiency forum
“Let us assume number of women teacher surveyed was W. Hence, number of men teacher surveyed was (1400 - W) Statement 1: 36% of men + 50% of women = 42% of 1400 Hence, 36*(1400 - W) + 50*W = 42*1400 We can solve W from the above equation. Sufficient Statement 2:As we don''t know the ...”
March 3, 2013
Anurag@Gurome posted a reply to conditional probability in the Problem Solving forum
“Number of outcomes with at least one head = 3 {HH, TH, HT} Number of outcomes with two heads = 1 {HH} Hence, required probability = 1/3 The correct answer is A.”
March 3, 2013
Anurag@Gurome posted a reply to conditional probability 2 in the Problem Solving forum
“We have three positions 1st, 2nd, and 3rd. For each position we have two choices, either boy or girl. But we know that the second position is already filled by a boy. Hence, total number of possibility for filling the positions = (2 choices for 1st position)*(2 choices for 2nd position) = 2*2 = 4 ...”
March 3, 2013
Anurag@Gurome posted a reply to Problem Solving - don't understand missing step in the Problem Solving forum
“Here 3x^2(x-2) means (3x²)*(x - 2), i.e. this is the product of 3x² and (x - 2) And, (-x + 2) = -(x - 2) = (-1)*(x - 2) Hence, the numerator = [(3x²)*(x - 2) - (-1)*(x - 2)] Now, we are taking (x - 2) out of bracket as it is a common factor of both the term, Hence, the numerator = (x - ...”
March 3, 2013
Anurag@Gurome posted a reply to The Department of Environmental Protection measured the vo in the Data Sufficiency forum
“Statement 1: As the new elements are (old element - some constant), the standard deviation won''t change. Sufficient Statement 2: As the new elements are (some constant)*(old element), the new standard deviation will be (same constant)*(old standard deviation) Now, if the old standard ...”
March 2, 2013
Anurag@Gurome posted a reply to A museum offers four video programs in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/really-challenging-word-problems-t115148.html#483757”
March 1, 2013
Anurag@Gurome posted a reply to Tangent problem in the Problem Solving forum
“I think a mathematical explanation will help you to analyze this kind of problems in future than remembering zillions of theorems and formulas. Take the two triangles OAC and OBC OB = OA (As they are radii of the larger circle) angle OCA = angle OCB (As the tangent (AB) is perpendicular to any ...”
March 1, 2013
Anurag@Gurome posted a reply to Sequences - DS in the Data Sufficiency forum
“No mathematics is needed here if you understand that "any term after S₂ is sum of the two terms Sn-1 and Sn-2" means any terms after S₂ is the sum of the previous two consecutive terms. Hence, if we know the values of S₁ and S₂, we can determine the value of any term after S₂. ...”
February 28, 2013
Anurag@Gurome posted a reply to geometry question in the Problem Solving forum
“In triangle GAF, FG = GA ---> GAF = GFA Now, GAF is nothing but DAE. Hence, GFA = DAE Hope that helps.”
February 28, 2013
Anurag@Gurome posted a reply to beat this if you can! in the Data Sufficiency forum
“I''d disagree here. There will be infinite parallelograms in the universe (with angles 45, 45, 135, 135) that has an area of 100. Without going into mathematical details, one can visualize that once we get one such parallelogram we can slightly "squeeze" it to change the length of the ...”
February 28, 2013
Anurag@Gurome posted a reply to Mixture/ratio problem . in the Problem Solving forum
“Amount of copper in the 20 kg bar of alloy = 5*20/(5 + 11) = 100/16 = 25/4 kg Let us assume that the weight of the first bar was x kg. Hence, weight of the 2nd bar was (20 - x) kg. Amount of copper in the x kg bar of alloy = 2*x/(2 + 5) = 2x/7 kg Amount of copper in the (20 - x) kg bar of alloy ...”
February 28, 2013
Anurag@Gurome posted a reply to If x and y are positive, is x < 10 < y in the Data Sufficiency forum
“Hope that helps.”
February 28, 2013
Anurag@Gurome posted a reply to If x and y are positive, is x < 10 < y in the Data Sufficiency forum
“Point to note : x and y are positive. hence, we can multiply or divide any inequality with either x or y without bothering about the inequality sign. Statement 1: x < y ---> x² < xy ---> x² < 100 ---> x < 10 Similarly, y > x ---> y² > xy ---> y² > 100 ...”
February 28, 2013
Anurag@Gurome posted a reply to probability question in the Problem Solving forum
“Total number of ways to select a group of 5 member from 9 candidates = 9C5 = 126 Required probability = 1 - C1)*(4C4)/126 = 5/126 Probability that the group attending the workshop will have exactly 2 students = (5C2)*(4C3)/126 = 10*4/126 = 40/126 Hence, required probability = 1 - (5/126 + ...”
February 28, 2013
Anurag@Gurome posted a reply to Really tough probability question in the Problem Solving forum
“Another method for solving this problem... Total number of ways to select the president, secretary and treasurer without any constraint = (10C1)*(9C1)*(8C1) = 10*9*8 Number of ways to select the president, secretary and treasurer such Harry is either Secretary or Treasurer = C1)*(1C1)*(8C1) + ...”
February 28, 2013
Anurag@Gurome posted a reply to Really tough probability question in the Problem Solving forum
“Required probability = 1 - [Probability that Harry is selected for president or Harry is not selected at all] Probability that Harry is selected for president = 1/10 Probability that Harry is not selected at all = (9/10)*(8/9)*(7/8) = 7/10 Hence, equired probability = 1 - [1/10 + 7/10] = 1 - ...”
February 28, 2013
Anurag@Gurome posted a reply to range in the Problem Solving forum
“Conceptually yes, but not in the format it has been posted.”
February 28, 2013
Anurag@Gurome posted a reply to range in the Problem Solving forum
“Let us assume the a is the smallest number and b is the largest number. Hence, b = (a + 2) Now let us consider the two extreme cases, When all the intermediate numbers are equal to the smallest sum = (9a + b) = (10a + 2) --> a = (28 - 2)/10 = 2.6 --> b = 4.6 When all the intermediate ...”
February 28, 2013
Anurag@Gurome posted a reply to Tough one - Math experts pls help for smart solution? in the Problem Solving forum
“This problem has been solved quite a number of times in this forum. Refer to the post here >> http://www.beatthegmat.com/coordinate-plane-t77573.html#345142”
February 28, 2013
Anurag@Gurome posted a reply to Number Properties in the Data Sufficiency forum
“The question asked whether k has a factor p such that 1 < p < k NOT whether k has all the factors p such that 1 < p < k. This means if there is at least one such p, the answer will be yes. Hence, if k = 13! + 3 = 1*2*3*4*...*12*13 + 3 = 3*(1*2*4*...*12*13 + 1) = Multiple of 3 Hence, ...”
February 27, 2013
Anurag@Gurome posted a reply to geometry question in the Problem Solving forum
February 27, 2013
Anurag@Gurome posted a reply to Tangent problem in the Problem Solving forum
“Algebraic Solution: Triangle OCB is a right-angled triangle with angle OCB = 90 degrees Hence, OC² + CB² = OB² --> r² + 6² = R² --> R² - r² = 36 --> (R - r)(R + r) = 36 As both r and R are positive integers, (R - r) and (R + r) must be integers too with (r + r) > (R - ...”
February 27, 2013
Anurag@Gurome posted a reply to Tangent problem in the Problem Solving forum
“Tricky Solution: Refer to the figure below http://s14.postimage.org/c1apyq6st/btg.jpg Say, radius of the inner circle = OC = r and radius of the larger circle = OB = R And, AC = CB = AB/2 = 6 Now, triangle OCB is a right-angled triangle with angle OCB = 90 degrees Hence, OC, CB, and CB ...”
February 27, 2013
Anurag@Gurome posted a reply to Help in the Data Sufficiency forum
“1. The first red line is redundant, as from the given equation itself we can deduce that x³ = x². 2. x = 1 as well as x = 0 both satisfy the equation.”
February 27, 2013
Anurag@Gurome posted a reply to ARITHMETIC - PROPERTIES OF NUMBERS in the Data Sufficiency forum
February 27, 2013
Anurag@Gurome posted a reply to help in the Data Sufficiency forum
“You can also check with picking some numbers. Consider the following two cases, p = 1, q = 1, s = 1, t = 2 --> Greatest = t p = -1, q = 1, s = 0, t = 0 ---> Greatest = q”
February 27, 2013
Anurag@Gurome posted a reply to help in the Data Sufficiency forum
“Yes, you are correct about the positive-negative scenario but decimal-fraction has nothing to do here. Both statements together: As average of q and r is s, s must be between q and r. And as sum of q and r is t, t must be smaller than both q and r, if both q and r are negative t must be greater ...”
February 27, 2013
Anurag@Gurome posted a reply to Help in the Data Sufficiency forum
“Statement 1: x³ - x² = 0 --> x²(x - 1) = 0 Hence, either x² = 0 or (x - 1) = 0 Hence, either x = 0 or x = 1 As we cannot uniquely determine the value of x, statement 1 alone is not sufficient Statement 2: (-x)² = -x² As (-x)² cannot be negative and -x² cannot be positive, the ...”
February 27, 2013
Anurag@Gurome posted a reply to number propeties in the Problem Solving forum
“Number of multiples of 3 between -100 and 100 = (Number of multiples of 3 between -1 and -100 + Number of multiples of 3 between -1 and -100) + 1 (for zero) Now, number of multiples of 3 between 1 and 100 = Number of multiples of 3 between -1 and -100 Number of multiples of 3 between 1 and 100 ...”
February 27, 2013
Anurag@Gurome posted a reply to greatest common factor in the Problem Solving forum
“GCF of 16 and n is 4 ---> n is multiple of 2 and 4 but not of 8 or 16 GCF of 45 and n is 3 ---> n is multiple of 2 but not of 5 or 9 Hence, n = 2*2*3*(Something) And, 210 = 2*3*5*7 Hence, we know for sure that GCF of 210 and n will be a multiple of both 2 and 3 but not of 4 or 5. But ...”
February 27, 2013
Anurag@Gurome posted a reply to DS_Quest in the Data Sufficiency forum
“Whenever problems with two sets (Say A and B) are involved always remember there are four scenarios - only A, only B, both and none. Now, A = only A + both B = only B + both Hence, Either A or B = A + B - both Total = Either A or B + None = A + B - Both + None For example, int his case a ...”
February 26, 2013
Anurag@Gurome posted a reply to Co-ordinate Geometry in the Data Sufficiency forum
“To determine the coordinates of the midpoint of a line segment, we need to know the coordinates of both the endpoints of the segment. Hence, none od the statements are individually sufficient. Let''s check whether together they are sufficient or not. 1 & 2 Together: x-coordinate of the ...”
February 26, 2013
Anurag@Gurome posted a reply to Remainder in the Data Sufficiency forum
“Hi Hemant! Although you have achieved the "correct answer" that too using the proper algebraic method, I''d chip in to point out a mistake which may be a silly mistake or a basic misconception. If a positive integer n leaves a remainder of 13 when divided by 25, n will either of the ...”
February 26, 2013
Anurag@Gurome posted a reply to Remainder in the Data Sufficiency forum
“n will be of the form (25m + 13), where m is some non-negative integer. Hence, possible values of n are 13, 38, 63, 88, 113, 138, 163 ... etc Statement 1: n can be 13 or 38 or 63 or 88 ---> Not sufficient Statement 2: n is also of the form (20n + 3), where n is some non-negative integer. ...”
February 26, 2013
Anurag@Gurome posted a reply to Number Properties in the Data Sufficiency forum
“Refer to the post here >> http://www.beatthegmat.com/integers-problem-t70990.html#320994”
February 26, 2013
Anurag@Gurome posted a reply to Babies born in the Data Sufficiency forum
“Yes, your reasoning is correct. However, this can solved without analyzing the statements as well. We know that x = (Number of single births) + (Number of double births) Now, number of double births will be always even. Hence, x = EVEN + Something If that something is even, x will be even ...”
February 26, 2013
Anurag@Gurome posted a reply to EQUATIONS + AVERAGE in the Data Sufficiency forum
“Let us assume, he bough W pairs of woolen socks and C pairs of cotton socks. And price of each pair of woolen socks and cotton socks are $n and$(n - 3), respectively. Hence, average price of a pairs of socks = Statement 1: C = 3W Hence, average price = Statement 2: (n - 3)C = 2nW Hence, ...”
February 26, 2013
Anurag@Gurome posted a reply to Inequalities in the Data Sufficiency forum
“Statement 1: xy > 0, x and y are of same sign zy > 0, z and y are of same sign Hence, x, y, and z are all of same sign. As we know nothing about the sign of either x or y, we can''t say whether z < 0 or not. Not sufficient Statement 2: We don''t know what is the relation between ...”
February 26, 2013
Anurag@Gurome posted a reply to absolute value in the Data Sufficiency forum
“y = |x + 3| + |4 - x| means y is the sum of the distances of x from -3 and 4 on the number line. Now the distance between -3 and 4 on the number line is (3 + 4) = 7. Hence, the sum of the distances of x from -3 and 4 on the number line will be equal to 7 only if x lies between -3 and 4. If it is ...”
February 26, 2013
Anurag@Gurome posted a reply to SOLVING EQUATIONS in the Data Sufficiency forum
“It is not given. The question asked whether (x + y) = 7 or not. You are taking that as supplied information, and putting back into the question. You can''t do that. Statement 1: Consider the following two examples, x = 0, y = 8 ---> (x + y) ≠ 7 x = 3, y = 4 ---> (x + y) = 7 Not ...”
February 26, 2013
Anurag@Gurome posted a reply to Ratios, Cola, Root Beer and Ginger in the Data Sufficiency forum
“When there are n unknowns, you need n independent equations to uniquely solve any of them (provided there is no constraints). Hence, if you go by this logic you''ll make a mistake to think that you need three equations to solve three unknowns because here we have a constraint, which is all the ...”
February 26, 2013
Anurag@Gurome posted a reply to ALGEBRA in the Data Sufficiency forum
“(k + m)² = k² + m² + 2km Hence, km = The correct answer is A.”
February 26, 2013
Anurag@Gurome posted a reply to Need help with this Manhattan Number properties guide Q in the Problem Solving forum
“Number of ways to select 2 marbles out of 10 marbles = 10C2 = 45 Number of ways to select one white and one blue marble = (Number of ways to select 1 white marble out of 2)*(Number of ways to select 1 blue marble out of 5) = 2*5 = 10 Hence, required probability = 10/45 = 2/9”
February 26, 2013
Anurag@Gurome posted a reply to Rate of decrease in the Data Sufficiency forum
“Statement 1: Say, mortality rate in 1972 is m Hence, mortality rate in 1976 is (0.9^4)*m Hence, percentage decrease = Statement 2: This is not enough to determine the required percentage as we do not know what happened to the mortality rate in the particular period 1972 to 1976 Not ...”
February 25, 2013
Anurag@Gurome posted a reply to Microchip price decline in the Problem Solving forum
“67% = 67/100 ≈ 2/3 Hence, every 6 months the price becomes (1 - 2/3) = 1/3 of the previous price. As 81 = 3^4, it''ll take 4 six months for the price to reach $1. 4 six months = 2 years The correct answer is B.” February 25, 2013 Anurag@Gurome posted a reply to Zero is a even integer in the Problem Solving forum “0 is multiple of every integer.” February 23, 2013 Anurag@Gurome posted a reply to Circle intersecting triangle in the Problem Solving forum “See the following figures: http://s2.postimage.org/1h4h7etgk/Circle_and_triangle.jpg Hence, correct answer is E.” February 23, 2013 Anurag@Gurome posted a reply to average in the Problem Solving forum “I couldn''t understand what you mean by "odd series of number". But if you are talking about a series of number in which number of terms is odd, then NO. For example, {1, 2, 9}. In this set median = 2 but mean = (1 + 2 + 9)/3 = 12/3 = 4 When all the elements of a set are ...” February 23, 2013 Anurag@Gurome posted a reply to Help Functions! in the Problem Solving forum “I think the simple format for representing the function introduced by Mitch is creating a bit confusion here. f_n(x) i.e. ''f subscript n'' as the image below is essentially different from f(x, n). http://s2.postimage.org/i72qs8mol/Code_Cogs_Eqn.jpg f_n(x) means the the primary variable of the ...” February 22, 2013 Anurag@Gurome posted a reply to Percentages with Variables in the Problem Solving forum “Let us assume x = 2, y = 100, and z = 100 Hence, x is 2% of y ---> n = 2 And, z is 100% of y ---> m = 100 And, x is 2% of z Hence, the correct option must be equal to 2 when n = 2 and m = 100 A. (n/m) = 2/100 ---> NO B. (m X n) = 200 ---> NO C. (100 / The correct answer is ...” February 22, 2013 Anurag@Gurome posted a reply to Percentages with Variables in the Problem Solving forum “What you found is ratio of x and z. Ratio is not same as percentage. I hope you understand your mistake now. If not, then look at your first line : "x is n%: x = (n / 100) * y" x is n% of y but x/y = n/100 Here x/z = n/m but x is 100*(n/m)% of z” February 22, 2013 Anurag@Gurome posted a reply to Permutation question - Combination in the Problem Solving forum “We have to select 8 members from (3 + 5 + 7 + 9) = 24 candidates Hence, total number of possible selections = 24C8 But some of these selections will have all the 5 sophomores in them which is not permitted by the condition "at most 4 Sophomores". We need to discard those selections. ...” February 21, 2013 Anurag@Gurome posted a reply to Fraction!!! in the Data Sufficiency forum “No. In number system, only an integer can be odd or even.” February 21, 2013 Anurag@Gurome posted a reply to DS - Decimals in the Data Sufficiency forum “Statement 1: x < 85/425 ---> x < 1/5 ---> x < 0.2 < 0.3 Hence, x is definitely not between 0.3 and 0.6 Sufficient Statement 2: x < 85/170 ---> x < 1/2 ---> x < 0.5 Now if x = 0.4 ---> x is between 0.3 and 0.6 But if x = 0.2 ---> x is not between 0.3 ...” February 21, 2013 Anurag@Gurome posted a reply to DS - Decimals and Ratio combined. in the Data Sufficiency forum “Always remember that any fraction whose denominator has only 2 and/or 5 as prime factors can be expressed as a terminating decimal. Otherwise, for example if the denominator has 3 or 7 or 11 etc as its prime factor, then the fraction can not be expressed as a terminating decimal. Statement 1: We ...” February 21, 2013 Anurag@Gurome posted a reply to Experts pl help Tough one : area of the largest circle in the Problem Solving forum “Note that the lines are parallel to each other. Hence, the largest circle that can be inscribed such that it is tangent to both lines will have diameter equal to the shortest distance between the two lines. Now, the most easiest method to solve this question is to use the following formula of ...” February 21, 2013 Anurag@Gurome posted a reply to If p = 5.18r7, what is the result when in the Problem Solving forum “Tricky Solution: Just by looking at the answer we can figure out that the answer will not depend upon the actual value of r. Hence, we can assume any value for r and solve the question. Say, r = 0 Hence, p = 5.1807 and p rounded to the nearest thousandth = 5.181 Hence, required answer = ...” February 21, 2013 Anurag@Gurome posted a reply to If p = 5.18r7, what is the result when in the Problem Solving forum “Algebraic Solution: p = 5.18r7, where r is an integer such that 0 ≤ r ≤ 9 If 0 ≤ r ≤ 8, p rounded to the nearest thousandth = 5.18q, where q is an integer such that 0 ≤ q ≤ 9 and q = (r + 1) In this case, required answer = (5.18q - 5.18r7) = 0.0003 If r = 9, p rounded to the ...” February 21, 2013 Anurag@Gurome posted a reply to How to solve these FUNCTIONS? in the Problem Solving forum “g(a + b, a + b) = f(a + b) + f(a + b) = 2*f(a + b) g(a, a) = f(a) + f(a) = 2*f(a) g(b, b) = f(b) + f(b) = 2*f(b) Hence, we need to find a function which satisfies the condition 2*f(a + b) = 2*f(a) + 2*f(b), i.e. f(a + b) = f(a) + f(b) This relation will satisfied only by linear functions. ...” February 21, 2013 Anurag@Gurome posted a reply to tough DS question ! in the Data Sufficiency forum “In one hour, Bonnie paints 1/x of the car Clyde paints 1/y of the car Together, they pain (1/x + 1/y) = (x + y)/xy of the car Hence, together they will take xy/(x + y) hour to finish painting the car Statement 1: Consider the following two case, x = 1 and y = 1 --> x = y x = 1 and y = ...” February 20, 2013 Anurag@Gurome posted a reply to Is |x−5|>4? in the Data Sufficiency forum “The question is asking whether the distance of x from 5 on the number line is greater than 4 or not. Statement 1: x² - 4 > 0 ---> x > 2 or x < -2 If x = 5 ---> |x - 5| = 0 < 4 If x = 10 ---> |x - 5| = 5 > 4 Not sufficient Statement 2: x² - 1 < 0 ---> -1 ...” February 20, 2013 Anurag@Gurome posted a reply to beat the DS from GMAT Club CAT in the Data Sufficiency forum “Statement 1: X² + YZ = XY + XZ --> X² - XY + YZ - XZ = 0 --> X(X - Y) - Z(X - Y) = 0 --> (X - Y)(X - Z) = 0 Hence, either (X - Y) = 0 or (X - Z) = 0 In both cases, (X - Y)(Y - Z)(X - Z) = 0 Sufficient Statement 2: XY - Y² = XZ - YZ --> XY - Y² - XZ + YZ = 0 --> ...” February 20, 2013 Anurag@Gurome posted a reply to question on number properties with square roots in the Problem Solving forum “Let us ignore the minus sign as of now. √5/5 = 1/√5 < 1 √7/7 = 1/√7 < 1 5/√5 = √5 > 1 7/√7 = √7 > 1 Now, √5 < √7 ---> 1/√5 > 1/√7 Hence, 1/√7 < 1/√5 < 1 < √5 < √7 Now, we''ll introduce the minus signs, i.e. we''ll multiply ...” February 20, 2013 Anurag@Gurome posted a reply to A particular library has 75 books in the Problem Solving forum “65% of loaned books were returned by the end of the month. Hence, 35% of the loaned books are not in the library by the end of the month. We know, (75 - 68) = 7 books are not in the library by the end of the month Hence, 35% of loaned books = 7 books Hence, number of loaned out books in that ...” February 20, 2013 Anurag@Gurome posted a reply to Number Properties in the Data Sufficiency forum “The question is simply asking whether k is even or not. Statement 1: k is divisible by 26, hence k is even ---> Sufficient Statement 2: As k is an integer greater than 1 but not divisible by any odd integer greater than 1, k must be an even integer ---> Sufficient The correct answer ...” February 19, 2013 Anurag@Gurome posted a reply to Real numbers!!! in the Problem Solving forum “Thanks for pointing it out, Ian. I completely missed the x = 0 scenario.” February 19, 2013 Anurag@Gurome posted a reply to Number Properties in the Data Sufficiency forum “Statement 1: We don''t know anything about k ---> Not sufficient Statement 2: We don''t know anything about j ---> Not sufficient 1 & 2 Together: As 30 = 2*3*5, j is divisible by at least 3 different prime numbers. Whereas k = 1000 = (2*5)^3 is divisible by only two different prime ...” February 19, 2013 Anurag@Gurome posted a reply to Real numbers!!! in the Problem Solving forum “Statement 1: By definition, if x is a nonnegative real number then √x is always nonnegative. As √x is not positive, then we can only conclude that x is not a positive real number. But x can be either equal to zero or a negative real number or not real at all. Not sufficient Statement 2: As ...” February 19, 2013 Anurag@Gurome posted a reply to what!!!! in the Problem Solving forum “Factors of 25 are 1, 5, and 25 Hence, x, y, and z must be any of these. Hence, x, y, ad z must be odd integers. Hence, the product xyz must be odd. The correct answer is D. If you want to know why others are always not true... A. x = y = z = 1 ---> xyz < 25 B. x = 1, y = 5, and z ...” February 19, 2013 Anurag@Gurome posted a reply to Soccer team - Veritas Question Bank in the Problem Solving forum “The selection groups are {1, 2}, {3, 4}, and {5, 6, 7} We can select only one number from each group. Now, 4 can be selected only if 2 is selected And, 3 can be selected only if 5 is selected If 1 is selected, we cannot select 4 and we have to select 3. Then we cannot select 6 or 7, we have ...” February 19, 2013 Anurag@Gurome posted a reply to Help! Practice Test Gone Wrong in the Data Sufficiency forum “Refer to the posts here << http://www.beatthegmat.com/gmat-prep-line-slope-t67624.html#304548 >> and here << http://www.beatthegmat.com/gmatprep-i-t72401.html#327945 >>” February 19, 2013 Anurag@Gurome posted a reply to Range of heights in the Data Sufficiency forum “I assume it''ll be "...the greatest height is h." Now, let us assume that least height of kids in A and B are respectively a and b. Hence, r = (g - a) and s = (h - b) Hence, a = (g - r) and b = (h - s) We need to determine whether a > b or not, i.e. (g - r) > (h - s) or ...” February 19, 2013 Anurag@Gurome posted a reply to Factorization in the Data Sufficiency forum “If the unit''s digit of any number is 0, then the number must be a multiple of 10, i.e. multiple of both 2 and 5. Statement 1: N is multiple of 14 and 25. Hence, N is a multiple of both 2 and 5. Sufficient Statement 2: Clearly N is multiple of both 2 and 5. Sufficient The correct ...” February 19, 2013 Anurag@Gurome posted a reply to Prime saturated in the Problem Solving forum “In other words, n will be prime saturated if the square of largest prime factor of n is smaller than n. Let''s check the options one by one... A. 6 = 2*3 ---> 3² > 6 ---> NO B. 35 = 5*7 ---> 7² > 35 ---> NO C. 46 = 2*23 ---> 23² > 46 ---> NO D. 66 = 2*3*11 ---> ...” February 18, 2013 Anurag@Gurome posted a reply to work and time in the Data Sufficiency forum “I''m assuming the read underlined load is same as the one in blue. Otherwise, answer is definitely going to be E. The question is asking whether all of them together will finish hauling the load in 15 minutes or not. To answer this we need to know the work capacity of the mules. 16 horses in ...” February 15, 2013 Anurag@Gurome posted a reply to 2^x - 2^(x-2) = 3(2^13) what is x? in the Problem Solving forum “Another tricky method to solve this problem is to expressing the right side of the expression as powers of of 2 only so that we can compare it with the left side. 3*(2^13) = (4 - 1)*(2^13) = (2^2 - 1)(2^13) = 2^15 - 2^13 = 2^15 - 2^(15 - 2) hence, x = 15” February 15, 2013 Anurag@Gurome posted a reply to 2^x - 2^(x-2) = 3(2^13) what is x? in the Problem Solving forum “2^(x - 2) = (2^x)*(2^(-2)) = (2^x)/(2^2) --> (2^x) - 2^(x - 2) = 3*(2^13) --> (2^x) - (2^x)/(2^2) = 3*(2^13) --> (2^2)*(2^x) - (2^x) = 3*(2^13)*(2^2) --> (2^x)*[(2^2) - 1] = 3*(2^15) --> 3*(2^x) = 3*(2^15) Comparing the both sides, x = 15” February 15, 2013 Anurag@Gurome posted a reply to MGMAT: Inequalities & Absolute Value (why did A.V. pop u in the Problem Solving forum “There is another way to solve this problem without bringing absolute values if you''re not confident with them. --> (x + 1)² < 36 --> (x + 1)² - 6² < 0 --> (x + 1 - 6)(x + 1 + 6) < 0 --> (x - 5)(x + 7) < 0 Hence, (x - 5) and (x + 7) are of opposite signs. Hence, ...” February 14, 2013 Anurag@Gurome posted a reply to MGMAT: Inequalities & Absolute Value (why did A.V. pop u in the Problem Solving forum “Just remember that by definition square root of any algebraic quantity x² is |x| Hence, square root of (x + 1)² is |x + 1|, square root of (x + y + z + 2xy + abc)² i |x + y + z + 2xy + abc| etc. For a more detailed explanation, refer to the post here >> ...” February 14, 2013 Anurag@Gurome posted a reply to Inequality - MGMAT in the Problem Solving forum “a²b > 1 ---> a² and b are of same sign As a² is always positive, b is also positive. Hence, a² > 1/b and 1/b > 1/2 Hence, a² > 1/2 Only option D works. The correct answer is D.” February 14, 2013 Anurag@Gurome posted a reply to Two More Tricky Problems for me in the Problem Solving forum “Refer to the posts as follows... For problem 1 >> http://www.beatthegmat.com/geometry-t131113.html#516326 For problem 2 >> http://www.beatthegmat.com/function-problem-t72321.html#327643” February 11, 2013 Anurag@Gurome posted a reply to y-intercept of line l? in the Problem Solving forum “If the slope and y-intercept of a line in xy plane are m and c respectively, then the line can be represented by the equation y = mx + c and the x=intercept of the line will be -c/m Statement 1: m = 3c ---> Not sufficient Statement 2: -c/m = -1/3 ---> m = 3c ---> Not sufficient 1 ...” February 11, 2013 aneesh.kg posted a new topic called Challenge #3: Percentages in the Data Sufficiency forum “The population of a city, which was X in January, increases by a certain amount in February of the same year and becomes Y. Then Y increases by a certain amount in March of the same year and becomes Z. Is the percentage change from X to Y greater than that from Y to Z? (1) Y - X = Z - Y (2) X = ...” February 10, 2013 Anurag@Gurome posted a reply to Another 800 problem in the Problem Solving forum “If x is not an integer, (x^2 + x + 1) also will not be integer. Now, if x is an integer, (x^2 + x + 1) = x(x + 1) + 1 = Product of two consecutive integers + 1 As product of two consecutive integers is always even, (x^2 + x + 1) will be odd. Hence, if (x^2 + x + 1) is a multiple of 5 it must be ...” February 5, 2013 Anurag@Gurome posted a reply to Tough problem in the Problem Solving forum “Method 2: Any perfect square can be written in the form (a + b)^2 = (a^2 + 2ab + b^2) Hence, we''ll try to write (2^2 + 2^5 + 2^n) in such manner. Now, if we take a^2 = 2^2 and 2ab = 2^5, then b = 2^3 = 8 Hence, (2^2 + 2*2*8 + 8^2) = (2 + 8)^2 = 10^2 Hence, 2^n = 8^2 = 2^6 Hence, n = 6 ...” February 5, 2013 Anurag@Gurome posted a reply to Tough problem in the Problem Solving forum “Method 1: (2^2 + 2^5 + 2^n) = (4 + 32 + 2^n) = (36 + 2^n) Note that (36 + 2^n) being a multiple of 2, cannot be a perfect square of an odd integer. Hence, if it is a perfect square, it must be a square of an even integer. Say, the even integer is 2m. So, (36 + 2^n) = (2m)^2 --> 2^n = ...” February 5, 2013 Anurag@Gurome posted a reply to 800+ problem in the Problem Solving forum “2013 = 3*11*61 Hence, 2013^2013 = (3*11*61)^(3*11*61) = C1 + 3C2 + 3C3 = 3 + 6 + 1 = 10 2012 = (2^2)*503 The situation similar to the previous one, but now we have two identical factors. Hence, number of pairs of x and y will be exactly half of the previous one, i.e. 10/2 = 5” February 5, 2013 Anurag@Gurome posted a reply to Some good examples to Exponents Questions in the Problem Solving forum “Question Number : 3 # 3*((a^2)^3) - 2*((a^3)^2) - (a^5) = 3*(a^6) - 2*(a^6) - a^5 = a^6 - a^5 The correct answer is C.” February 5, 2013 Anurag@Gurome posted a reply to Some good examples to Exponents Questions in the Problem Solving forum “Question Number : 2 a^(y - x) = a^(-(x - y) = 1/The correct answer is C.” February 5, 2013 Anurag@Gurome posted a reply to Some good examples to Exponents Questions in the Problem Solving forum “Question Number : 1 y = 2^x Now, 2^(x + 3) = (2^x)*(2^3) = 8*(2^x) = 8y The correct answer is E.” February 5, 2013 Anurag@Gurome posted a reply to Mean, Standard deviation in the Problem Solving forum “Say, mean score = M and standard deviation = D Hence, 58 = M - 2S and 98 = M + 3S So, (M + 3S) - (M - 2S) = 98 - 58 --> 5S = 40 --> S = 8 Hence, M = (58 + 2S) = (58 + 2*8) = (58 + 16) = 74 The correct answer is A.” February 4, 2013 aneesh.kg posted a reply to Challenge#1 (Modulus/Absolute Value) in the Data Sufficiency forum “Statement 1: x = (3)^0.3 or - (3)^0.5 INSUFFICIENT Statement 2: x = Modulus of something Therefore x must be 0 or greater than zero INSUFFICIENT Combining the two, x = (3)^0.5, which is positive. Therefore, is correct.” February 1, 2013 aneesh.kg posted a reply to Challenge#1 (Modulus/Absolute Value) in the Data Sufficiency forum “Hemanth, good try! But is not the correct answer. Lets modify the problem slightly to make two new problems. Modification 1: Is x non-negative? (1) |x^2| = 3 (2) |6 - 5y| = x Modification 2: If y is an integer, is x positive? (1) |x^2| = 3 (2) |6 - 5y| = x If you solve these, ...” January 30, 2013 aneesh.kg posted a reply to Challenge#2 (Numbers/Exponents) in the Problem Solving forum “Thank you Brent! I''d solve this in a similar fashion, albeit without oversimplification. (Maybe you did that for the sake of explaining well) The difference between D and B is twice the difference between each consecutive element. D - B = 3^15 - 3^13 = 3^13 * (3^2 - 1) = 8 * 3^13 ...” January 30, 2013 aneesh.kg posted a reply to ABSOLUTE VALUES (CONFUSION!!) in the Data Sufficiency forum “I don''t think I understand your query very well. y has two possible values from the second statement: -8 and 14. When you are combining the two statements you can substitute these two values in statement(1) to see with which one of the values does Statement(1) agree. Substitute ''-8'': 3 ...” January 29, 2013 aneesh.kg posted a reply to ABSOLUTE VALUES (CONFUSION!!) in the Data Sufficiency forum “Yes, there are exceptions. Let me clear a few things here. Misconception: ''whenever there is an absolute value question, one obtains two values'' NO. One normally obtains two values. You may also obtain ZERO, just ONE, more than two or INFINITELY MANY solutions in an absolute value problem. ...” January 29, 2013 aneesh.kg posted a new topic called Challenge#2 (Numbers/Exponents): in the Problem Solving forum “C#2: If A, B, C and D are evenly spaced on the number line as shown below A....B....C....D and B = 3^13 and D = 3^15, then what is the value of A? (A) 3^12 (B) 4(3^13) (C) - 4(3^13) (D) - 3^12 (E) - 3^14 OA after sometime. Source: self-designed” January 29, 2013 aneesh.kg posted a new topic called Challenge#1 (Modulus) in the Data Sufficiency forum “Hi people, Here''s a tricky problem on modulus. I gave this problem to my students in my class today and everybody made mistakes in their first attempt. Lets see if you guys can get it right in the first attempt. C#1: Is x positive? (1) |x^2| = 3 (2) |6 - 5y| = x OA after some time. ...” January 29, 2013 Anurag@Gurome posted a reply to Rectangle or quadrilateral in the Problem Solving forum “Any four-sided shape is a Quadrilateral. But the sides have to be straight, and it has to be 2-dimensional. A rectangle is a four-sided shape where every angle is a right angle (90°). Also opposite sides are parallel and of equal length. A square has equal sides and every angle is a right ...” January 28, 2013 Anurag@Gurome posted a reply to Medium Difficulty Exponents/variables in the Data Sufficiency forum “Please note that we are not given in the question that variables can only take integer values. (1) 5^a = 25 implies 5^a = (5)^2 implies a = 2, bit we do not know the value of b; NOT sufficient. (2) c = 36 implies (3)^a * (4)^b = 36 If a = 2, and b = 1, then (3)^2 * (4)^1 = 36 Since we are ...” January 25, 2013 Anurag@Gurome posted a reply to 65 or older overlapping sets in the Data Sufficiency forum “Already discussed: http://www.beatthegmat.com/idea-of-overlapping-sets-t112758.html#474556” January 25, 2013 Anurag@Gurome posted a reply to Carlos the racer in the Data Sufficiency forum “Distance = speed * time or d = st, where d = distance, s = speed (in mph), t = time Question is: Is d > 6? or is st > 6 or is s * (1/2) > 6 implies is s > 12 mph Now convert mph to feet per sec: 12 miles per hour = (12 * 5280)/(60 * 60) = 17.6 feet per sec So, the question is: Is s ...” January 25, 2013 Anurag@Gurome posted a reply to Probability with balls in the Data Sufficiency forum “Already discussed here: http://www.beatthegmat.com/probability-gmatprep-cat-t118795.html” January 25, 2013 Anurag@Gurome posted a reply to divisibility in the Data Sufficiency forum “I have posted a solution here: http://www.beatthegmat.com/is-x-a-multiple-of-y-t85339.html” January 25, 2013 Anurag@Gurome posted a reply to Overlap issues in the Problem Solving forum “Now, R = 10*P, A = 20*PR, A = 5*P, and (A + RA + PA + PRA) = 210 Hence, PR = A/20, P = A/5, and R = 10*P = 2*A #> R + A + P + RA + PA + PR + PRA = 435 #> R + P + PR + (A + RA + PA + PRA) = 435 #> 2*A + A/5 + A/20 + 210 = 435 #> (40*A + 4*A + A)/20 = (435 - 210) = 225 #> 45*A = ...” January 23, 2013 Anurag@Gurome posted a reply to Proportionality in the Problem Solving forum “Refer to the post here >> http://www.beatthegmat.com/chemical-reaction-t107218.html#454716” January 23, 2013 Anurag@Gurome posted a reply to left handed or right? in the Problem Solving forum “Thanks for pointing it out. Edited the solution.” January 23, 2013 Anurag@Gurome posted a reply to left handed or right? in the Problem Solving forum “Total number of people in either town = Tall + Left-handed - Both + Neither Say, number of tall, left-handed, both and neither people in town X are T, L, B, and N, respectively. Hence, the same in town Y are 3T, 3L, 3B, and 0, respectively. Now, total number of people in X = total number of ...” January 23, 2013 Anurag@Gurome posted a reply to Tricky Roots in the Problem Solving forum “A. x = 2, G(2) = 2^(1/2) B. x = 3, G(3) = (2*3)^(1/3) = 6^(1/3) C. x = 5, G(5) = (2*3*5)^(1/5) = 30^(1/5) D. x = 7, G(7) = (2*3*5*7)^(1/7) = 210^(1/7) E. x = 11, G(11) = (2*3*5*7*11)^(1/11) = 2310^(1/11) Note that G(2), G(3),... and G(11) are greater than 1. Hence, whatever the order of them ...” January 23, 2013 Anurag@Gurome posted a reply to Henry Saving Money in the Problem Solving forum “Let Henry spends$x and he saves $y. This implies total income =$(x + y) Then, next year Henry spends $y(1 + r) = x/2 implies x = 2y(1 + r) We have to find y/(x + y) = y/The correct answer is E.” January 22, 2013 Anurag@Gurome posted a reply to Coordinate Plane - triangle in the Problem Solving forum “Here''s one more approach, other than the one already explained by Brent. Formula for finding area of a triangle in a coordinate system = (1/2){(x1 - x2).(y2 - y3) - (y1 - y2).(x2 - x3)} In the given question, area of triangle = 1/2 {(-3)(1) - (-4).(7)} = 12.5 sq units The correct answer is ...” January 22, 2013 Anurag@Gurome posted a reply to Linear Sequence Problem in the Problem Solving forum “Let the height by which the tree increased constantly each year be x ft. At the end of the 1st year, height of tree = 4 + x At the end of the 2nd year, height of tree = 4 + 2x ... At the end of the 6th year, height of the tree = 4 + 6x It is given that at the end of the 6th year, the tree ...” January 21, 2013 Anurag@Gurome posted a reply to Problem solving integer question in the Problem Solving forum “h(100) = 2 * 4 * 6 * ... * 100 = (2 * 1) * (2 * 2) * (2 * 3) * ... * (2 * 50) = 2^(50) * (1 * 2 * 3 ... * 50) Then h(100) + 1 = 2^(50) * (1 * 2 * 3 ... * 50) + 1 Now, h(100) + 1 cannot have any prime factors 50 or below, because dividing this value by any of these prime numbers will give a ...” January 21, 2013 Anurag@Gurome posted a reply to The number of 75 can be written as the sum in the Problem Solving forum “Refer to the post: http://www.beatthegmat.com/sum-of-squares-of-3-different-positive-integers-t100899.html” January 21, 2013 Anurag@Gurome posted a reply to Number properties problem in the Problem Solving forum “Refer to the post: http://www.beatthegmat.com/then-t-is-gmat-prep-t115193.html” January 21, 2013 Anurag@Gurome posted a reply to Alice's take-home pay last year was the same each month in the Problem Solving forum “Refer to the post: http://www.beatthegmat.com/alice-s-take-home-package-t72398.html#327957” January 21, 2013 Anurag@Gurome posted a reply to Word problem - Distance question in the Data Sufficiency forum “Refer to the post here >> http://www.beatthegmat.com/distance-t131130.html#516349” January 21, 2013 Anurag@Gurome posted a reply to Multiples of 11 between 100 and 500 ---- 37 or 36? :-( in the Problem Solving forum “This formula always holds only when the "Biggest" and "Smallest" are both multiple of the "distance" in question. If they are not, then sometimes it will hold and sometimes it will not. Let me clarify with some example, Number of multiples of 11 between 1 and 12 is ...” January 15, 2013 Anurag@Gurome posted a reply to number of Atendees? in the Problem Solving forum “EDIT : This post had a mistake. I posted an algebraic solution here >> http://www.beatthegmat.com/number-of-atendees-t159845.html#553851.” January 15, 2013 Anurag@Gurome posted a reply to number of Atendees? in the Problem Solving forum “Let us assume total number of attendees = N Now, 2N/3 are females --> N/3 are non-female And, N/3 are students Number of female students = N/6 Hence, number of non-female students = (N/3 - N/6) = N/6 Hence, number of non-female non-students = (number of non-female - number of non-female ...” January 15, 2013 Anurag@Gurome posted a reply to lights on vs lights off? in the Problem Solving forum “Refer to the post here >> http://www.beatthegmat.com/hotel-california-t84377.html#372102” January 15, 2013 Anurag@Gurome posted a reply to If i and d are integers, what is the value of i? (1) The re in the Data Sufficiency forum “Algebraic Approach: Statement 1: i = md + r and i = n(d + 2) + r, where m and n are some non-negative integers. This means i = Statement 2: i = d*(d + 2) + r This is nothing but a modified version of statement 1 and we still can have different combination of values for i, d, and r. Not ...” January 15, 2013 Anurag@Gurome posted a reply to If i and d are integers, what is the value of i? (1) The re in the Data Sufficiency forum “Consider the following two examples, d = 2, (d + 2) = 4 --> i = 9 d = 3, (d + 2) = 5 --> i = 16 Both the above examples satisfies both the statements but value of i is different in both cases. The correct answer is E.” January 15, 2013 Anurag@Gurome posted a reply to Questions on ranges in the Problem Solving forum “The range of the selling prices in May was$15,000 and the lowest selling price was $4,500, so the highest price in May = 15000 + 4500 =$19,500 The range of the selling prices in June was $16,500 and the lowest selling price was$6,100, so the highest price in June = 16500 + 6100 = $22,600 ...” January 14, 2013 Anurag@Gurome posted a reply to Shortcut approach --Ratio/Proportion in the Problem Solving forum “Let the three containers contain 3x, 4x and 5x liters of mixtures respectively. Milk in 1st container = (4/5) * 3x = (12x)/5 Water in 1st container = 3x - (12x/5) = (3x)/5 Milk in 2nd container = (3/4) * 4x = 3x Water in 2nd container = 4x - 3x = x Milk in 3rd container = (5/7) * 5x = (25x)/7 ...” January 8, 2013 Anurag@Gurome posted a reply to Combinatorics problem: in the Problem Solving forum “Casey should go 5 block down and 4 block left to travel exactly 9 blocks (DDDDDLLLL). Required no. of days = 9!/(5!)(4!) = (9 * 8 * 7 * 6)/(4 * 3 * 2) = 3 * 7 * 6 = 126” January 8, 2013 aneesh.kg posted a new topic called Pune GMAT Prep in the GMAT Strategy forum “Hello GMAT Aspirants from Pune, My name is Aneesh, and I''m an IIT Alumnus. I''ve been helping people for GMAT over the past 19 months and must''ve helped over 200 GMAT students till date. (I handle the QA section). I have also been heavily active on this community. I''ve taught a variety of ...” January 3, 2013 Anurag@Gurome posted a reply to DS Question 2 in the Data Sufficiency forum “Refer to the post here >> http://www.beatthegmat.com/mean-median-of-sets-any-easy-method-t82370.html#362403” January 3, 2013 Anurag@Gurome posted a reply to Fill an order - Rate my answer explanation in the Data Sufficiency forum “Your solution perfectly fine.” January 3, 2013 Anurag@Gurome posted a reply to Smallest prime factor of product of even numbers in the Problem Solving forum “Each term of (2*4*6*8*10*...*100) is multiple of 2. I''m just taking one 2 from each term out of the bracket. Hence, I''m taking fifty 2s out of the bracket. For example, (2*4*6*8) can be written as [(2*1)*(2*2)*(2*3)*(2*4)] = (2*2*2*2)*(1*2*3*4) = (2^4)*(1*2*3*4) Hope that helps.” January 2, 2013 Anurag@Gurome posted a reply to Quadratic Equation Problem_2 in the Problem Solving forum “If m and n are the roots of the quadratic equation ax² + bx + c = 0, then (m + n) = -b/a mn = c/a √(b/a) + √(a/b) = (a + b)/√(ab) Let us assume the roots of the quadratic equation px² + rx + r = 0 are ax and bx. Hence, (ax + bx) = -r/p and abx² = r/p Hence, (a + b) = -r/(px) and ...” January 2, 2013 Anurag@Gurome posted a reply to Can prime numbers be negative numbers as well? in the Data Sufficiency forum “No. Prime numbers are by definition natural numbers, i.e. positive integers. Consider the following two examples, x = 5 and y = 3 ---> (x - y) = 2 is prime integer ---> (x + y) = 8 x = 5 and y = 2 ---> (x - y) = 3 is prime integer ---> (x + y) = 7 Both of the above examples ...” January 1, 2013 Anurag@Gurome posted a reply to Remainder of positive integer x ? in the Data Sufficiency forum “Statement 1: This means x is an odd multiple of 3. Hence, x is of the form 3*(2m + 1) where m is some non-negative integer. Hence, x = 3*(2m + 1) = 6m + 3 = Some multiple of 6 + 3 Hence, x will leave a remainder of 3 when divided by 6. Sufficient Statement 2: x is of the form 12n + 3 where ...” January 1, 2013 Anurag@Gurome posted a reply to Smallest prime factor of product of even numbers in the Problem Solving forum “This question has been discussed many times in the forum. h(100) + 1 = (2*4*6*8*10*...*100) + 1 = (2^50)*(1*2*3*4*5*...*50) + 1 Thus when The correct answer is E.” December 31, 2012 Anurag@Gurome posted a reply to Is x > y^2 ? in the Data Sufficiency forum “Thanks for pointing it out vinni. I''ve edited my reply.” December 31, 2012 Anurag@Gurome posted a reply to Border of photograph in the Problem Solving forum “Adding a figure to what Param800 explained. I hope drawing a figure helps you more to understand. http://s9.postimage.org/h01ok55jf/rect.jpg” December 31, 2012 Anurag@Gurome posted a reply to Algebric Properties in the Problem Solving forum “The odd-even concept is not valid for real numbers. To be even or odd, a real number have to be an integer first. For integers, these properties always hold true. You can also check this with the help of examples: (1) 2 + 4 = 6 (True) (2) 4 - 2 = 2 (True) (3) 1 + 3 = 4 (True) (4) 3 - 1 = 2 ...” December 31, 2012 Anurag@Gurome posted a reply to GMAT Prep - Data Sufficiency Question in the Data Sufficiency forum “The correct question is: At a certain pet shop, 1/3 of the pets are dogs and 1/5 of the pets are birds. How many of the pets are dogs? (1) There are 30 birds at the pet shop. (2) There are 20 more dogs than birds at the pet shop. Let the total number of pets = P, birds = B and dogs = D. ...” December 31, 2012 Anurag@Gurome posted a reply to Marble Menace in the Data Sufficiency forum “Statement 1: Say the total number of marbles in the bag is N and there are R red marbles. Hence, there are (N - R) blue marbles. Number of ways to select two marbles from N marbles = NC2 = N(N - 1)/2 Number of ways to select one red marble from R marbles and one blue marbles from (N - R) marbles ...” December 29, 2012 Anurag@Gurome posted a reply to Is x > y^2 ? in the Data Sufficiency forum “Statement 1: Consider the following two examples, x = 0 and y = -10 ---> x < y² x = 6 and y = 0 ---> x > y² Not sufficient Statement 2: Consider the following two examples, x = 2 and y = 2 ---> x < y² x = 1/2 and y = 1/2 ---> x > y² Not sufficient 1 & 2 ...” December 29, 2012 Anurag@Gurome posted a reply to Probability Problem in the Problem Solving forum “The probability that the box will be cleared for shipment = The probability that all the five toys in the box are not defective = (1 - 0.1)^5 = (0.9)^5 Hence, the probability that the box will not be cleared for shipment = 1 - (0.9)^5 The correct answer is E.” December 29, 2012 Anurag@Gurome posted a reply to Maths problem in the Problem Solving forum “(4^5 - 16) = (4^5 - 4^2) = (4^2)*(4^3 - 1) = (2^4)*(64 - 1) = (2^4)*63 = (2^4)*7*9 = (2^4)*(3^2)*7 Hence, the greatest prime factor of (4^5 - 16) is 7” December 29, 2012 Anurag@Gurome posted a reply to GMAT Prep Question in the Problem Solving forum “Refer to the post here >> http://www.beatthegmat.com/tough-problem-solving-gmac-test-t113380.html#476827” December 29, 2012 Anurag@Gurome posted a reply to D.S. Dhamaka III : Probability in the Data Sufficiency forum “As for both statements, we can definitely determine all the elements of set A and set B, we can definitely calculate the required probabilities. Hence, we can compare them and answer the question with definite YES or NO. Hence, both statements are individually sufficient to answer the question. ...” December 28, 2012 Anurag@Gurome posted a reply to D.S. Dhamaka II : Work-Rate and Percentages in the Data Sufficiency forum “To be strict, there is no mention that all these particular tasks are same task. Hence, the answer should be E as we cannot relate any of the statement with the question. Assuming they are same task, Statement 1: Say time taken by 5 women to complete the task is 100x hours. Hence, time taken ...” December 28, 2012 Anurag@Gurome posted a reply to D.S. Dhamaka I : Averages. in the Data Sufficiency forum “Say, number of students in class A and B are x and y, respectively. Hence, the average score of the two classes taken together = (60x + 75y)/(x + y) Statement 1: x = 50% more than y = 150% of y = (150/100)*y = 3y/2 Hence, the average score of the two classes taken together = (60x + 75y)/(x + y) ...” December 28, 2012 Anurag@Gurome posted a reply to Another one in Perm & Comb in the Problem Solving forum “The question is asking us to arrange three out of five letters in a straight line, not to arrange all the five letters. Also the question has some ambiguity in the word "together". If "never together" means A and B will not be placed side by side, then the solution is as ...” December 28, 2012 Anurag@Gurome posted a reply to Is m < 0 ? in the Data Sufficiency forum “Statement 1: By definition |m| = -m if and only if m ≤ 0 Hence, we can conclude that m less than or equal to zero. Not sufficient Statement 2: m² = 9 Hence, either m = -3 or m = 3. Not sufficient 1 & 2 Together: m must be equal to -3 < 0 Sufficient The correct answer is ...” December 28, 2012 Anurag@Gurome posted a reply to Speed-Time Problem. in the Problem Solving forum “Average speed for 2m miles = 5v/3 miles per hour Hence, time taken to travel 2m miles = 2m/(5v/3) hours = 6m/5v hours Average speed for first m miles = v miles per hour Hence, time taken to travel first m miles = m/v hours Hence, time taken to travel the final m miles = (6m/5v - m/v) hours = ...” December 28, 2012 Anurag@Gurome posted a reply to Product of two two-digit numbers in the Problem Solving forum “I assume that you have no problem in understanding how we can deduce Y = 1. Assuming that, we know the product of the two-digit numbers X1 and 1X is a three digit number XZX. Now, X1 = (10*X + 1) = 10X + 1 And, 1X = (10*1 + X) = 10 + X And, XZX = (100X + 10Z + X) So, X1*1X = XZX --> ...” December 27, 2012 Anurag@Gurome posted a reply to Need help with this in the Problem Solving forum “Refer to the post here >> http://www.beatthegmat.com/shortcut-or-formula-for-sum-of-consecutive-integers-needed-t114474.html#481045” December 27, 2012 Anurag@Gurome posted a reply to Smallest positive factor PS. Help. in the Problem Solving forum “There is no definite answer to this question. As our requirement is n must have two 5s and one 3, we can find the minimum positive value for n. But the maximum value of n can be the largest possible positive multiple of 75 which we cannot definitely determine.” December 27, 2012 Anurag@Gurome posted a reply to Smallest positive factor PS. Help. in the Problem Solving forum “Please check your source. I think the original question is as follows... Say, N = n × 2^5 × 6^2 × 7^3 If 5^2 and 3^3 are factors of N, then N must contain two 5s and three 3s. Now, 2^5 × 6^2 × 7^3 does not contain any 5. But it does contain two 3s in 6^2 = (2*3)^2 Hence, the ...” December 26, 2012 Anurag@Gurome posted a reply to problem6 in the Problem Solving forum “Can you post the figure please?” December 23, 2012 Anurag@Gurome posted a reply to problem10 in the Problem Solving forum “After this point the problem can be solved easily without actually solving the quadratic equation, if we remember that (6, 8, 10) constitutes a Pythagorean triplet. Hence, 6² + 8² = 10² and (8 - 6) = 2 Hence, the cafe is 8 miles from Karen’s house.” December 23, 2012 Anurag@Gurome posted a reply to problem10 in the Problem Solving forum “http://s1.postimage.org/kedezl80b/gurome.jpg Refer to the figure above. C is the Cafe, D is Dan''s house and K is Karen''s house. Hence, the hypotenuse, KD = 10 And if KC = x, CD = (x - 2) So, x² + (x - 2)² = 10² = 100 --> x² + x² - 4x + 4 = 100 --> 2x² - 4x - 96 = 0 --> ...” December 23, 2012 Anurag@Gurome posted a reply to problem9 in the Problem Solving forum “The problem cannot be solved without the assumption that there can be no ties or draws in any game. The team either wins or loose. The team has played (17 + 3) = 20 games till now. Hence, 2/3 of total number of games = 20 Hence, total number of games = 20*(3/2) = 30 and number of remaining ...” December 23, 2012 Anurag@Gurome posted a reply to PROBLEM8 in the Problem Solving forum “The first and last integer between 100 and 200 which are divisible by 3 are 102 and 198. Hence, number of integers between 100 and 200 that are divisible by 3 = number of integers between 102 and 198 (both inclusive) that are divisible by 3 = (198 - 102)/3 + 1 = 96/3 + 1 = 32 + 1 = 33 The ...” December 23, 2012 Anurag@Gurome posted a reply to problem7 in the Problem Solving forum “Say, the cost of the gift is$P. Hence, Al contributed $(P/3 - 2) and Lew contributed$(P/4 + 2). So, P - (P/3 - 2) - (P/4 + 2) = 15 --> P - P/3 - P/4 = 15 --> P - 7P/12 = 15 --> 5P/12 = 15 --> P = 36 The correct answer is C.”
December 23, 2012
Anurag@Gurome posted a reply to problem5 in the Problem Solving forum
“Fries = 2*Cloeslaw Hamburger + Coleslaw = Hamburger + Fries/2 = $3.59 ........... (1) Hamburger + Fries =$4.40 ...................................... (2) Subtracting (1) from (2), Fries/2 = $(4.40 - 3.59) =$0.81 Hence, price of french fries = $(2*0.81) =$1.62 Check your source. None ...”
December 23, 2012
Anurag@Gurome posted a reply to time n work problem in the Problem Solving forum
“6 men do the work in 30*9 = 270 hours 25 days of 8 hours = 25*8 hours = 200 hours To complete ten times of the work in 200 hours number of men required = 6*270*10/200 = 3*27 = 81”
December 22, 2012
Anurag@Gurome posted a reply to problem4 in the Problem Solving forum
“As there must be equal number of students in each row, the number of row must be a factor of 180. All the options are factors of 180 except 40. Hence, the correct answer is D.”
December 21, 2012
Anurag@Gurome posted a reply to problem3 in the Problem Solving forum
“4*(1/8) = 1/2 As the culture of bacteria quadruples every hour, in one hour it will grow from 1/8 full to half full. Hence, it was 1/8 full at 9:00 AM. The correct answer is A.”
December 21, 2012
Anurag@Gurome posted a reply to Problem2 in the Problem Solving forum
“√0.0026 = √(0.0001*26) = (√0.0001)*√26 Now, √0.0001 = 0.01 and √26 ≈ 5 Hence, √0.0026 ≈ 0.01*5 = 0.05 The correct answer is A.”
December 21, 2012
Anurag@Gurome posted a reply to Problem in the Problem Solving forum
“1 year = 12 months = 52 weeks If the person pay by week, then in one year he pays 52*10 = $520 If the person pay by month, then in one year he pays 12*30 =$360 Hence, saving = $(520 - 360) =$160 The correct answer is B.”
December 21, 2012
Anurag@Gurome posted a reply to Probability in the Problem Solving forum
“Yes, you can but the red part is wrong. Probability of drawing a red marble in exactly two draw = (Probability of drawing a red marble)*(Probability of drawing a red marble)*(Probability of drawing a blue marble) = (12/30)*(12/30)*(18/30) = (2/5)*(2/5)*(3/5) = 12/125 Now this can happen in 3C2 ...”
December 18, 2012
Anurag@Gurome posted a reply to Spheres in the Problem Solving forum
“Surface area of B is 300% higher than that of A. Hence, surface area of B is four times the surface area of A. As, surface area of a sphere is proportional to the square of the radius, radius of B must be twice of the radius of A. Now, volume of a sphere is proportional to the cube of the ...”
December 17, 2012
Anurag@Gurome posted a reply to Tom reads at an average rate of 30 pages per hour, whil in the Problem Solving forum
“Say, after t minutes from 5:20, they''ll be reading the same page. Then in t minutes, Jan has to read 25 pages and the pages Tom have read in t minutes. Now, in t minutes, Tom will read t/2 pages Jan will read 2t/3 pages Hence, in t minutes Jan will read 2t/3 pages which must be equal to (25 ...”
December 17, 2012
Anurag@Gurome posted a reply to Remainder in the Problem Solving forum
“Yes, that''s correct.”
December 17, 2012
Anurag@Gurome posted a reply to Each employee of company Z is an employee of Division X in the Data Sufficiency forum
“Let us assume number of full-time employees for division X = Xf Number of part-time employees for division X = Xp Number of full-time employees for division Y = Yf Number of part-time employees for division Y = Yp Then question is: Is Xf/Xp > (Xf + Yf)/(Xp + Yp)? or is XfXp + XfYp > ...”
December 17, 2012
Anurag@Gurome posted a reply to Set T is an infinite sequence of positive integers. A " in the Problem Solving forum
“Puneet, that''s a copy-paste of my previous post :)”
December 17, 2012
Anurag@Gurome posted a reply to Set T is an infinite sequence of positive integers. A " in the Problem Solving forum
“See my post here: http://www.beatthegmat.com/set-question-t72444.html”
December 17, 2012
Anurag@Gurome posted a reply to 344. During an experiment, some water was removed from each in the Problem Solving forum
“(1) It is given that 30% of the volume of water is removed from all the tanks so standard deviation remains same; SUFFICIENT. (2) The average (arithmetic mean) volume of water in the tanks at the end of the experiment was 63 gallons does not help in finding the standard deviation of the volumes ...”
December 17, 2012
Anurag@Gurome posted a reply to Remainder in the Problem Solving forum
“To maximize (r^2 + R), we need to maximize both r and R. Now, maximum value of r, i.e. maximum value of the remainder when any number is divided 4 is 3. And, maximum value of R, i.e. maximum value of the remainder when any number is divided 9 is 8. Hence, the maximum value of (r^2 + R) is ...”
December 16, 2012
Anurag@Gurome posted a reply to How many different ways can 2 students be seated in a r in the Problem Solving forum
“The possible scenarios are, 1. They are occupying 1st and 3rd seat 2. They are occupying 2nd and 4th seat 3. They are occupying 1st and 4th seat Hence, 3 ways. As the two student can be arranged in two ways in each of the above possible scenarios, total number of ways are 2*3 = 6 The ...”
December 16, 2012
Anurag@Gurome posted a reply to Find the number of pairs of positive integers (x, y) su in the Problem Solving forum
“--> (x^6 - y^2) = 127 --> (x^3 - y)(x^3 + y) = 127 As 127 is a prime number, it can be expressed as the product of two integers in only one way, i.e. 1*127 Hence, either (x^3 - y) = 1 and (x^3 + y) = 127 --> x = 4 and y = 63 OR (x^3 - y) = 127 and (x^3 + y) = 1 --> x = 4 ...”
December 16, 2012
Anurag@Gurome posted a reply to Unit digit in the Problem Solving forum
“The given product is multiple of 2 and 5, i.e multiple of 10. Hence, the unit''s digit of the product is 0. The correct answer is A.”
December 16, 2012
Anurag@Gurome posted a reply to Tom reads at an average rate of 30 pages per hour, whil in the Problem Solving forum
“In 1 minute, Tom reads 1/2 page Jan reads 2/3 page 4:30 to 5:20 = 50 minutes In 50 minutes Tom has already read 50/2 = 25 pages Say, after t minutes from 5:20, they''ll be reading the same page. Then in t minutes, Jan has to read 25 pages and the pages Tom have read in t minutes. Hence, ...”
December 16, 2012
Anurag@Gurome posted a reply to If two of the four expressions x+y,x+5y,x-y and 5x-y ar in the Data Sufficiency forum
“(x + y)(x + 5y) = x^2 + 6xy + 5y^2: Not in the form x^2- (by)^2 (x + y)(5x - y) = 5x^2 + 4xy - y^2: Not in the form (x + 5y)(x - y) = x^2 + 4xy - 5y^2: Not in the form (x + 5y)(5x - y) = 5x^2 + 24xy - 5y^2: Not in the form (x - y)(5x - y) = 5x^2 - 6xy + y^2: Not in the form (x + y)(x - y) ...”
December 15, 2012
Anurag@Gurome posted a reply to Statistics Problem Set in the Problem Solving forum
“Let the list S be 2n + 1, 2n + 3, 2n + 5,…..,2n + 19 where n is an integer. Let list T be 2k, 2k + 2, 2k + 4,…2k + 8. Now 2n+1 - 2k = 7. Or 2n - 2k = 6. Also, average of the integers in S is (4n + 20)/2 = 2n + 10. Average of integers in T is 2k + 4. So, difference is (2n + 10) - (2k + ...”
December 14, 2012
Anurag@Gurome posted a reply to Is x^3 > x^2 ? in the Data Sufficiency forum
“(1) x > 0 If x = 2, then x^3 = 8, x^2 = 4. Here x^3 > x^2. If x = 1/2, then x^3 = 1/8 = 0.125 and x^2 = 1/4 = 0.25. Here x^3 < x^2. No definite answer; NOT sufficient. (2) x² > x If x = 2, then x² = 4 and x^3 = 8. Here x^3 > x^2. If x = -2, then x² = 4 and x^3 = -8. Here ...”
December 13, 2012
Anurag@Gurome posted a reply to Decimals Ds Question in the Data Sufficiency forum
“Posted a solution here: http://www.beatthegmat.com/decimals-t114862.html”
December 11, 2012
Anurag@Gurome posted a reply to Formulas and Functions in the Problem Solving forum
“If x0 = xn = 0 and if xk = 15, then the series will be: 0, 3, 6, 9, 12, 15,... So, x(k + 1) = 12 implies the series is ..., 12, 9, 6, 3, 0 Hence the sequence, x0, x1, x2, x3......., xn will be: 0, 3, 6, 9, 12, 15, 12, 9, 6, 3, 0. It can be seen that there are 11 terms in the sequence. So, x(n + ...”
December 10, 2012
Anurag@Gurome posted a reply to How many of tables are in the warehouse? in the Problem Solving forum
“Say the number of tables = n Now total number of possible combination = (Number of ways to select 2 chairs out of 5)*(Number of ways to select 2 tables out of n) = (5C2)*(nC2) = 10*(nC2) Now, 10*(nC2) = 150 => (nC2) = 15 => n(n - 1)/2 = 15 => n(n - 1) = 30 Now we can solve this ...”
December 10, 2012
Anurag@Gurome posted a reply to OG-12 Problem 156 Pg 286 in the Data Sufficiency forum
“I posted a solution here: http://www.beatthegmat.com/three-tough-ds-questions-t85242.html”
December 5, 2012
Anurag@Gurome posted a reply to Time before 2880717 minutes! in the Problem Solving forum
“Without going into detailed calculations we can solve this problem just by looking at the options. Time now is 6:27. So when we go back a huge amount of minutes which ends with 7, the time then should end with 0. Thus, only feasible option is 6:30 The correct answer is D.”
December 5, 2012
Anurag@Gurome posted a reply to Quantitative Review 2nd Edition DS Question 57 -Pg157 in the Data Sufficiency forum
“(1) m > 0 m/n = 5/3 If m = 5, n = 3, then m + n = 8 If m = 15, n = 9, then m + n = 24 No definite answer; NOT sufficient. (2) 2m + n = 26 m/n = 5/3 m = 5n/3 So, 2(5n/3) + n = 26 10n + 3n = 78 13n = 78 n = 6 implies m = (5 * 6)/3 = 10; SUFFICIENT. The correct answer is B.”
December 5, 2012
Anurag@Gurome posted a reply to How to find out the last two digits of 14^40 in the Problem Solving forum
“This problem can be easily solved by remembering the blue colored fact. 14^40 = (2*7)^40 = (2^40)*(7^40) Now, 7^4 = 2401. Hence, 7^4 raised to any power will end in ...01. Hence, last two digits of 7^40 = (7^4)^10 is 01. And, 2^10 = 1024 24 raised to any odd power ends with 24 and 24 ...”
December 5, 2012
Anurag@Gurome posted a reply to Greatest common divisor in the Data Sufficiency forum
“(1) m is a prime number but there is info about n; NOT sufficient. (2) m and n are consecutive integers. Any two consecutive positive integers are co-prime, which implies that they share 1 as the common factor. For example: 3 and 4, 5 and 6, are consecutive integers and they share 1 as the ...”
December 3, 2012
Anurag@Gurome posted a reply to Distance from line in the Problem Solving forum
“The point that will be equidistant from the points (1, 11) and (7, 7) will be the midpoint of the line passing through these points. Coordinates of the midpoint will be {(1 + 7)/2, (11 + 7)/2} = (4, 9) Now slope of a line passing through the two points (x1, y1) and (x2, y2) = (y2 - y1)/(x2 - ...”
December 2, 2012
Anurag@Gurome posted a reply to data sufficiency in the Problem Solving forum
“As jnicholson explained, we can do this by picking numbers approach. (1) w + 2 > 0 If w = 2, then w + 2 = 4 > 0. Here w > 1. If w = -1, then w + 2 = -1 + 2 = 1 > 0. Here w < 1. No definite answer; NOT sufficient. (2) w² > 1 If w = 2, then w² = 4 > 1. Here w > 1. ...”
December 1, 2012
Anurag@Gurome posted a reply to A certain cake has two layers - Gmat Prep in the Data Sufficiency forum
“Let us assume that all the fruits in both layers = T Then strawberries = 25% of T = 0.25T Also, 0.25T = strawberries in layer 1 + strawberries in layer 2 (1) Of the pieces of fruit on the first layer, 6 are strawberries. 0.25T = 6 + strawberries in layer 2, but we do not know number of ...”
December 1, 2012
“(1) a/b = 5/8 a and b can take any values like: a = 5, b = 8 or a = 10, b = 16 Since a and b can take any value, so value of a + b also varies accordingly. No definite answer; NOT sufficient. (2) The greatest common divisor of a and b is 1 implies a and b can be any co-prime numbers; NOT ...”
December 1, 2012
Anurag@Gurome posted a reply to Least possible value of x in the Problem Solving forum
December 1, 2012
Anurag@Gurome posted a reply to Least possible value of x in the Problem Solving forum
“Let 3x=4y=7z = n. Then x = n/3, y = n/4 and z = n/7 x+y+z = n/3 + n/4 + n/ 7 = 61n/84 Since x , y and z are positive integers so x + y + z should also be a positive integer, this implies minimum value of n = 84 Hence, minimum value of x + y + z = 61 The correct answer is D.”
December 1, 2012
Anurag@Gurome posted a reply to Let ax + by = c in the Problem Solving forum
“Since (8, 12) lies on ax + by = c, so 8a + 12b = c ... Equation 1 Algebraically, an x-intercept is a point on the graph where y is zero, or it is a point in the equation where the y-value is zero. When y = 0, then ax + 0 = c or ax = c It is given that x-intercept of the line is 2. So, 2a = c. ...”
December 1, 2012
Anurag@Gurome posted a reply to What is the value of the positive integer m? in the Data Sufficiency forum
“(1) m² = 2m m² - 2m = 0 m(m - 2) = 0 m = 0 or m = 2 m = 0 is not possible as m is given to be a positive integer. Hence, m = 2; SUFFICIENT. (2) m is even. m cab be any even integer, so this info is definitely NOT sufficient. The correct answer is A.”
November 29, 2012
Anurag@Gurome posted a reply to Pumps A, B, and C in the Problem Solving forum
November 27, 2012
Anurag@Gurome posted a reply to Pumps A, B, and C in the Problem Solving forum
“In 1 hour, A can empty 1/3 of the tank B can empty 1/2 of the tank C can fill 1/6 of the tank Hence, in one hour, working together they empty (1/3 + 1/2 - 1/6) = 4/6 = 2/3 of the tank. Hence, to empty 1/2 of the tank, they will take (3/2)*(1/2) hours = 3/4 hours = 45 minutes”
November 27, 2012
Anurag@Gurome posted a reply to Distance speed Time in the Problem Solving forum
“In one day A fills 1/5 of the pool and B fills 1/3 of the pool. Hence, in one day together they fill (1/5 + 1/3) = 8/15 of the pool Hence, after one day, (1 - 8/15) = 7/15 of the pool is empty which should be filled by A. A takes 5 days to fill the entire pool. Hence, to fill 7/15 of the ...”
November 27, 2012
Anurag@Gurome posted a reply to The rooms on the south side of the corridor in the Problem Solving forum
November 27, 2012
Anurag@Gurome posted a reply to A certain Internet service provider in the Problem Solving forum
“$0.75 per hour =$0.75/60 per minute For first ten hours she has to pay $5.95 The excess of$(9.50 - 5.95) = $3.55 she will pay at the rate of$0.75/60 per minute So, the extra usage she will get = 3.55*60/0.75 minutes = 355*60/75 minutes = 355*4/5 minutes = 71*4 minutes = 284 minutes = 4 ...”
November 27, 2012
Anurag@Gurome posted a reply to A certain box contains in the Problem Solving forum
“Tricky Approach: Say, the total number of pencils in the box = N Now after removing one red pencil, number of blue pencil = number of red Hence, N must be odd. Only possible options are A, B, and D. And after removing one blue pencil, 2*(number of blue pencil) = number of red pencil. ...”
November 27, 2012
Anurag@Gurome posted a reply to A certain box contains in the Problem Solving forum
“Algebraic Approach: Say, number of red pencils in the box = R and number of blue pencils in the box = B Now, (R - 1) = B And, R = 2(B - 1) Hence, B = 2(B - 1) - 1 = 2B - 3 ---> B = 3 Hence, R = (B + 1) = 4 The correct answer is D.”
November 27, 2012
Anurag@Gurome posted a reply to If k is the smallest three-digit positive in the Problem Solving forum
“144 can be expressed as the product of three single digit positive integers in any of the following ways... 2*8*9 3*6*8 4*4*9 4*6*6 The smallest three digit positive integer that can be formed with any of the above sets of integers is 289. The correct answer is B.”
November 27, 2012
Anurag@Gurome posted a reply to sour milk in the Problem Solving forum
“Amount of fat in x gallons of 1% grade = x*(1/100) = x/100 gallons Amount of fat in y gallons of 2% grade = y*(2/100) = (2y)/100 gallons Amount of fat in z gallons of 3% grade = z*(3/100) = (3z)/100 gallons Amount of fat in (x + y + z) gallons of 1.5% grade = (x + y + z)*(1.5/100) = The correct ...”
November 25, 2012
Anurag@Gurome posted a reply to freaking function in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/gmat-function-problem-t91975.html#411296”
November 25, 2012
Anurag@Gurome posted a reply to Please solve it in the Problem Solving forum
“(19^26 + 33^26) = (26 - 7)^26 + (26 + 7)^26 Now, every term except the last term of the expansion of (26 - 7)^26 and (26 + 7)^26 will be a multiple of 26. The last term of both the expansions are 7^26 which is not multiple of 26. Hence, the remainder will be equal to the remainder when (7^26 + ...”
November 25, 2012
Anurag@Gurome posted a reply to Please solve it in the Problem Solving forum
“Mathematical Approach: --> (a + b + c)(b + c - a) = kbc --> (b² + c² - a² + 2bc) = kbc --> (b² + c² - a²) = (kbc - 2bc) Now, cosine of angle A in a triangle is given by cos A = (b² + c² - a²)/(2bc) Hence, cos A = (b² + c² - a²)/(2bc) = (kbc - 2bc)/(2bc) = (k - 2)/2 ...”
November 25, 2012
Anurag@Gurome posted a reply to Please solve it in the Problem Solving forum
“The proper mathematical approach for solving this problem is well beyond the reach of GMAT. So I''m going to solve this problem using picking number approach. (a + b + c) is always positive and as the sum of two sides of a triangle is always greater than the third side, (b + c - a) is also ...”
November 25, 2012
Anurag@Gurome posted a reply to Please solve it in the Problem Solving forum
“f(x) = x³ - 4x - p Hence, f(0) = -p and f(1) = -(3 + p) Hence, p and (3 + p) are of opposite signs. If p < 0, (3 + p) > 0 --> p > -3 --> -3 < p < 0 If p > 0, (3 + p) < 0 --> p < - 3 --> Not possible The correct answer is D.”
November 25, 2012
Anurag@Gurome posted a reply to solve it please in the Problem Solving forum
“Refer to the post here >> http://www.beatthegmat.com/please-solve-it-t145992.html#534356”
November 24, 2012
Anurag@Gurome posted a reply to GMAT Club - Probability in the Problem Solving forum
“The diameters are... 1. X-axis --> slope = 0 2. Y-axis --> slope = infinity 3. x = y --> slope = 1 4. x = -y --> slope = -1 There 4C2 = 6 possible pairs of diameter. Among them only the product of slopes of 3 and 4 will be -1. Hence, required probability = 1/6 The correct ...”
November 24, 2012
Anurag@Gurome posted a reply to please solve it in the Problem Solving forum
“Group B contains 20 questions of 3 marks each --> 20*3 = 60 marks Let us assume group A contains x questions and group C contains y questions. Hence, (x + y) = (150 - 20) = 130 Total marks of the 150 questions = (2x + 60 + 5y) Now, the questions in group A together carry at least 40% of ...”
November 24, 2012
Anurag@Gurome posted a reply to DS Topic Ratios - GMAT Tomorrow in the Data Sufficiency forum
“Say the number of men, women and children in the sightseeing tour are m, w and c respectively. Thus, w:c = 5:2 = (5/2) : 1 Statement 1: c:m = 5:11 = 1: (11/5) Hence, m:w:c = (11/5) : (5/2) : 1 = 22:25:10 Thus, the possible numbers can be (22, 25, 10) or integer multiples of that like (44, 50, ...”
November 24, 2012
Anurag@Gurome posted a reply to Interesting Problem;HELP GMAT Tomorrow in the Data Sufficiency forum
“Let us assume that C = Cost, T = thickness, L = Length, k = constant of proportionality C = k * L * T² (1) The cost of a square slab that is 2 meters long and 0.2 meter thick is $160 more than the cost of a square slab that is 2 meters long and 0.1 meter thick. C = k * 2 * (0.2)² = 0.08k C = ...” November 24, 2012 Anurag@Gurome posted a reply to Standard Deviation Problem;HELP GMAT Tomorrow in the Data Sufficiency forum “(1) It is given that 30% of the volume of water is removed from all the tanks so standard deviation remains same; SUFFICIENT. (2) The average (arithmetic mean) volume of water in the tanks at the end of the experiment was 63 gallons does not help in finding the standard deviation of the volumes ...” November 24, 2012 Anurag@Gurome posted a reply to Median Problem;HELP GMAT Tomorrow in the Problem Solving forum “Median of a set of 15 different integers will be the 8th integer of the series when arranged according to their values. Now, Largest - Smallest = Range => Largest = (Smallest + Range) As the range is fixed, we can maximize largest number by maximizing the smallest number. Maximum ...” November 24, 2012 Anurag@Gurome posted a reply to combinatorics in the Problem Solving forum “Number of possible one-letter codes = 26 Number of possible two-letter codes = 26*26 Number of possible three-letter codes = 26*26*26 Hence, total number of possible codes = 26 + 26*26 + 26*26*26 No need to calculate the above. Just notice that unit''s digit of all the underlined term ends ...” November 23, 2012 Anurag@Gurome posted a reply to PS Topic Combinations - GMAT Tomorrow in the Problem Solving forum “Number of notepads of the same color = 4 (blue, green, yellow, pink) Since there are two different sizes, so total number of notepads for the same color = 4 * 2 = 8 We have to choose 3 different colors from 4, so notepads of different colors = 4C3 = 4 Since there are two different sizes, so ...” November 23, 2012 Anurag@Gurome posted a reply to PS Topic Percentages - GMAT Tomorrow in the Problem Solving forum “Rate of a certain chemical reaction, R, is directly proportional A²/B When the concentration of chemical B is increased by 100 percent, then concentration of chemical A also increases by, say, a%. Then, R = A²/B = (aA)²/2B A²/B = a²A²/2B 1 = a²/2 a² = 2 a = 1.4, which means there ...” November 23, 2012 Anurag@Gurome posted a reply to Little tricky one: in the Data Sufficiency forum “(1) Median is the value that separates the upper and lower half of the sample. (1) gives that 25% of projects have 4 or more employees to each project . But the % of projects that have less than 4 employees is not given. So, (1) is NOT SUFFICIENT. (2) From this statement, the % of projects that ...” November 22, 2012 Anurag@Gurome posted a reply to OG-12 #50 in the Problem Solving forum “Obviously, l23-5yl is least when 5y is closest to 23. Multiple of 5 closest to 23 is 25 and this makes y as 5. Or l23-5yl is least as l23-25l = 2. The correct answer is B.” November 20, 2012 Anurag@Gurome posted a reply to Odd even- in the Problem Solving forum “Now 96 is the product of 3 single digit numbers. 96 = 12 * 8 = 3*4*8 = 2*6*8 =4*4*6. So the units digit, tens digit and hundreds digit can be either 3, 4 and 8 or 2, 6 or 8 or 4, 4, 6 in any order. Consider first statement (1) alone. m is odd. So the units digit of m is odd. Only ...” November 19, 2012 Anurag@Gurome posted a reply to Minimum possible population in the Problem Solving forum “Let us assume that the minimum possible population = x Then the maximum population = x + 10% of x = 1.1x For x to be minimum, only one district should have minimum possible population, while the other 10 districts should have the same population, which is equal to 1.1x So, x + 1.1*10x = 132000 ...” November 15, 2012 Anurag@Gurome posted a reply to Abstract number problem in the Problem Solving forum “(I) x > y^2 Certainly for integer values of x and y, x is always greater than y. But what about fractional values> f y is a fraction then y^2 is < y. Now always there is a fraction x, such that y > x > y^2. Thus for fractional values x may be less than y. Therefore regarding the ...” November 15, 2012 Anurag@Gurome posted a reply to Tough question-2 in the Problem Solving forum “http://s14.postimage.org/dfer14zjx/Pat.jpg For the length to be minimum, Pat should eight go upwards or right. So, for this he goes 3 steps up and then 2 steps right or 2 steps right and then 3 steps up, which makes 5 steps in all. So, number of routes from X to Y that Pat can take having the ...” November 15, 2012 Anurag@Gurome posted a reply to Help needed for two questions I met in Prep!! in the Problem Solving forum “I. x² < 2x < 1/x If x = 2, then x² = 4, 2x = 2 and 1/x = 1/2 implies 4 < 2 < 1/2, which is NOT the correct ordering. II. x² < 1/x < 2x If x = 3, then x² = 9, 2x = 6 and 1/x = 1/3 implies 9 < 1/3 < 6, which is NOT the correct ordering again. III. 2x < x² ...” November 14, 2012 Anurag@Gurome posted a reply to Help needed for two questions I met in Prep!! in the Problem Solving forum “h(100) = 2 * 4 * 6 * ... * 100 = (2 * 1) * (2 * 2) * (2 * 3) * ... * (2 * 50) = 2^(50) * (1 * 2 * 3 ... * 50) Then h(100) + 1 = 2^(50) * (1 * 2 * 3 ... * 50) + 1 Now, h(100) + 1 cannot have any prime factors 50 or below, because dividing this value by any of these prime numbers will give a ...” November 14, 2012 Anurag@Gurome posted a reply to Diameter in the Problem Solving forum “As triangle ABC is equilateral, arc ABC is 2/3 of the circumference of the circle. Hence, circumference of the circle = 24*3/2 = 36 Hence, diameter of the circle = 36/π = Slightly less than 36/3 ≈ 11 The correct answer is A.” November 8, 2012 Anurag@Gurome posted a reply to G.C.F and L.C.M in the Data Sufficiency forum “Picking Numbers Approach: Statement 1: Consider the following two cases, x = 10 and y = 20 ---> xy = 200 x = 10 and y = 30 ---> xy = 300 Not sufficient Statement 2: Consider the following two cases, x = 4 and y = 45 ---> xy = 180 x = 90 and y = 180 ---> xy = 90*1800 ...” November 8, 2012 Anurag@Gurome posted a reply to G.C.F and L.C.M in the Data Sufficiency forum “Product of two positive integers = (LCM of the integers)*(GCF of the integers) Hence, we need both the statements to answer the question. The correct answer is C.” November 8, 2012 Anurag@Gurome posted a reply to The annual rent in the Data Sufficiency forum “Let the rent collected in 1997 = R Then rent collected in 1998 = R + Rx/100 = R(1 + x/100) Rent collected in 1999 = R(1 + x/100) - y% of R(1 + x/100) = R(1 + x/100)(1 - y/100) Question is: Is R(1 + x/100)(1 - y/100) > R? OR Is 1 + x/100 - y/100 - xy/10000 > 1? OR Is x - y > xy/100? ...” November 7, 2012 Anurag@Gurome posted a reply to I can't solve this!! in the Problem Solving forum “You can look at these explanations: http://www.beatthegmat.com/problem-solving-t123088.html” November 6, 2012 Anurag@Gurome posted a reply to OG 13 Q52 in the Data Sufficiency forum “I think the first statement is: x < y and xy = 100 (1) x < y and xy = 100 It is given that both x and y are positive and x < y. So, for xy = 100 to be true, one multiple should be < 10 and the other should be > 10. Therefore, x < 10 < y; SUFFICIENT. (2) x² < 100 < ...” November 6, 2012 Anurag@Gurome posted a reply to Percentages in the Problem Solving forum “(1) In 1970 the population of city k was 160,000. But this alone is NOT sufficient to find the desired percent increase in population. (2) In 1980, the population of city k was 20 % greater than it was in 1970 and in 1990 the population of city k was 30% greater than it was in 1970. Let us ...” November 3, 2012 Anurag@Gurome posted a reply to factoring in the Problem Solving forum “(1) The greatest common factor of x and y is 10. If x = 10, y = 10, then GCF of x and y = 10. Here xy = 10 * 10 = 100 If x = 10, y = 30, then GCF of x and y = 10. Here xy = 10 * 30 = 300 No definite answer; NOT sufficient. (2) The LCM of x and y is 180. If x = 10, y = 180, then LCM of x and y ...” November 3, 2012 Anurag@Gurome posted a reply to combination in the Problem Solving forum “No. of ways of selecting 2 chairs from 5 chairs = 5C2 Let us assume that no. of tables in the warehouse = n Then no. of ways of selecting 2 tables from n tables = nC2 Then 5C2 * nC2 = 150 5!/{(2!) * (5 - 2)!} * n!/{(2!) * (n - 2)!} = 150 (5 * 4 * 3!)/(2! * 3!) * n!/{(2!) * (n - 2)!} = 150 (5 ...” November 3, 2012 Anurag@Gurome posted a reply to number line in the Problem Solving forum “n is to the left of 0 on the number line, i.e. n < 0 As n² < 1/100, n lies between -1/10 and 1/10 Hence, -1/10 < n < 0 --> 1/n < -10 The correct answer is A.” November 3, 2012 Anurag@Gurome posted a reply to units and tens in the Problem Solving forum “Let us assume that r = xyz, where tens digit = y. We have to find the value of y. (1) The tens digit of r/10 is 3. r/10 = xy.z, which implies that tens digit is x. So, x = 3, but we cannot find y from here; NOT Sufficient. (2) The hundreds digits of 10r is 6. 10r = xyz0, which implies ...” November 3, 2012 Anurag@Gurome posted a reply to function in the Problem Solving forum “Picking Numbers Approach: If x = 1, then 1 - x = 1 - 1 = 0 We have to find for which of the functions f(1) = f(0). (A) f(1) = 1 - 1 = 0, and f(0) = 1 - 0 = 1; NOT True (B) f(1) = 1 - 1² = 0, and f(0) = 1 - (0)² = 1; NOT True (C) f(1) = 1² - (1-1)² = 1, and f(0) = 0² - (1 - 0)² = ...” November 3, 2012 Anurag@Gurome posted a reply to function in the Problem Solving forum “Let us look at each of the options: (A) f(x) = 1-x f(1-x) = 1 - (1-x) = x; FALSE (B) f(x) = 1-x^2 f(1-x) = 1 - (1-x)^2 = 1 - (1 - 2x + x^2) = 2x - x^2; FALSE (C) f(x) = x^2 - (1-x)^2 f(1-x) = (1-x)^2 - (1 - (1-x))^2 = 1 - 2x + x^2 - (x)^2 = 1 - 2x; FALSE (D) f(x) = x^2 * ...” November 3, 2012 Anurag@Gurome posted a reply to sequence in the Problem Solving forum “Let x and y be the number of 7''s and the number of 77''s respectively. Then 7x + 77y = 350 implies x + 11y = 50 x + y = 50 - 10y So, x + y = n = 50 - 10y implies n must have the unit digit of 0 because 50 - 10y must be a number which has units digit as 0. C is the only option in which the ...” November 3, 2012 Anurag@Gurome posted a reply to Number Prop in the Problem Solving forum “(1) 2x - 2y = 1 implies x - y = 1/2 or x = y + (1/2) If y = 4, then x = 4 + (1/2) = 5/2 = positive If y = -3/2, then x = (-3/2) + (1/2) = -1 = negative No definite answer; NOT sufficient. (2) x/y > 1 implies x and y could be both positive or both negative. No definite answer; NOT ...” November 3, 2012 Anurag@Gurome posted a reply to distance in the Problem Solving forum “Time would have taken if speed was x mph, T = 40/x hour Time taken in current situation, t = The correct answer is B.” November 3, 2012 Anurag@Gurome posted a reply to Mixture problems in the Problem Solving forum “The correct answer is A.” November 3, 2012 Anurag@Gurome posted a reply to Percentages in the Problem Solving forum “Let us assume that no. of males = M and no. of females = F Then the question is to find the value of M/(M + F). (1) Of this year graduating students, 33% of the males and 20% of the females transferred from another college implies 0.33M and 0.20F of of M males and F females are transferred from ...” November 3, 2012 Anurag@Gurome posted a reply to Number Prop in the Problem Solving forum “Let total animals = T cows = C and Pigs = P Then (2/3) of 60 = P + C or P + C = 40 (1) C > 2P, It is NOT SUFFICIENT as there can be many possibilities. (2) P > 12, It is NOT SUFFICIENT as there can be many possibilities. Combining (1) and (2), If P = 13, then C > 26, so that ...” November 3, 2012 Anurag@Gurome posted a reply to Geometry in the Problem Solving forum “The length of one piece = 2(pi)r and the other is a square. Let us assume that each side of the square is "a". Perimeter of square = 4a Now, 2(pi)r + 4a = 40 4a = 40 - 2(pi)r a = The correct answer is E.” November 3, 2012 Anurag@Gurome posted a reply to PS Queries - Need expert help One day left for the GMAT in the Problem Solving forum “Question is: For every integer k from 1 to 10, inclusive, the kth term of a certain sequence is given by (-1)^(k+1) x (1/2^k). If "T" is the sum of the first 10 terms in the sequence, then T is: A. greater than 2 B. between 1 and 2 C. between 1/2 and 1 D. between 1/4 and 1/2 ...” November 1, 2012 Anurag@Gurome posted a reply to PS Queries - Need expert help One day left for the GMAT in the Problem Solving forum “The Question is: if n denotes a number to the left of 0 on the number line such that the square of n is less than 1/100, then the reciprocal of n must be a. less than -10 b. between -1 and -1/10 c. between -1/10 and 0 d. between 0 and 1/10 e. greater than 10 Explanation: n is to ...” November 1, 2012 Anurag@Gurome posted a reply to PS Queries - Need expert help One day left for the GMAT in the Problem Solving forum “Let the envelopes be E1, E2, E3, E4 and the corresponding letters be L1, L2, L3, L4. Suppose L1 goes to E1 and the other letters do not go in their corresponding envelopes. So, E2 will have either L3 or L4 If E2 has L3, E3 will have L4, E4 will have L2. If E2 has L4, E3 will have L2, E4 will ...” November 1, 2012 Anurag@Gurome posted a reply to DS Queries - Need Expert help One day left for the GMAT in the Data Sufficiency forum “Consider the following two cases, x = 2, y = -1, z = 1 ---> YES x = 2, y = -1, z = 3 ---> NO Both of the above cases satisfy both the statements but the answer is first case is YES and in the second is NO. Hence, both statements together is also NOT sufficient. The correct ...” November 1, 2012 Anurag@Gurome posted a reply to DS Queries - Need Expert help One day left for the GMAT in the Data Sufficiency forum “Equation of a line in point intercept form is y = mx + b, where m is the slope of the line, b is the y-intercept of the line. The question is to find the value of b. (1) The slope of line l is 3 times its y-intercept implies m = 3b, which is not enough to find b; Not SUFFICIENT. (2) ...” November 1, 2012 Anurag@Gurome posted a reply to DS Queries - Need Expert help One day left for the GMAT in the Data Sufficiency forum “(1) 2x - 2y = 1 x and y both positive means that point (x, y) is in the first quadrant. 2x - 2y = 1 implies y = x - 1/2, and it''s an equation of a line and the question asks whether this line is only in first quadrant, which is not possible; NOT sufficient. (2) x/y > 1 x and y have the ...” November 1, 2012 Anurag@Gurome posted a reply to DS Queries - Need Expert help One day left for the GMAT in the Data Sufficiency forum “(1) m - 3z > 0; NOT sufficient. (2) 4z - m > 0; NOT sufficient. Combining (1) and (2), adding inequalities in statements (1) and (2), (m - 3z) + (4z - m) > 0 or z > 0 (we can add inequalities with the sign in the same direction) or z is positive. So, m is also positive. Hence m + z ...” November 1, 2012 Anurag@Gurome posted a reply to is x positive in the Data Sufficiency forum “Sum of first n terms of a geometric progression is, S = a(r^n - 1)/(r - 1), where a = first term, r = common ratio, which is not equal to 1, and n = number of terms Now in this case if we take a = 1, r = x, and n = 11, then Sum = (x^11 - 1)/(x - 1) (1) x < -1 implies (x^11 - 1)/(x - 1) = ...” November 1, 2012 Anurag@Gurome posted a reply to value of xy in the Data Sufficiency forum “(1) 3^x * 5^y = 75 3^x * 5^y = 3 * 5² Comparing both the sides (since bases on both sides are the same), we get, x = 1, and y = 2; SUFFICIENT. (2) 3^((x−1)(y−2)) = 1 is clearly NOT sufficient to find the values of x and y. The correct answer is A.” November 1, 2012 aneesh.kg posted a reply to Day 6 - Data Sufficiency Practice (OG, 13th Ed), Problem 148 in the GMAT Math forum “Let me try. When you divide anything by 4, you''re basically dividing that thing in four equal parts. Let''s take a rod of length 1 foot. When you divide it into four equal parts (same as performing 1/4), the length of each piece would be 0.25 feet. If the rod were of length 2 feet, 3 feet and ...” October 30, 2012 aneesh.kg posted a reply to Who needs socks? in the Problem Solving forum “If you pick 4 socks from these 20 socks, you are bound to have atleast one pair (or two socks) of socks of the same colour. e.g. WWBG, WBBG, WBGG, WWGG, etc. Think of a possibility where all the four socks are of different colours? You can''t. Because there are just three colours avavilable, ...” October 30, 2012 Anurag@Gurome posted a reply to Probability - HELP in the Problem Solving forum “Probability that the first rosebush will be white = 2/4 Now there are 2 reds out of total 3 rosebushes left, so probability that the second rosebush will be red = 2/3 Now one red rosebush out of total 2 rosebushes is left, so probability that the third rosebush will be red = 1/2 Now, one white ...” October 29, 2012 Anurag@Gurome posted a reply to Product of two integers in the Data Sufficiency forum “A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. Here we have to find if k is a prime number. (1) k² has one more positive factor than k. If k is a prime then it has 2 factors, 1 and k implies k² has 3 factors: 1, k, and k². If k = 1 ...” October 29, 2012 Anurag@Gurome posted a reply to Numbers in the Problem Solving forum “Dividend = Quotient * Divisor + Remainder n = 17x + 5 ... Equation 1 n = 23y + 14 ... Equation 2 Equating the value of n from the 2 equations above, 17x + 5 = 23y + 14 17x - 23y = 9 The correct answer is B.” October 22, 2012 Anurag@Gurome posted a reply to Percent in the Problem Solving forum “Algebraic Method: Total no. of rats = R No. of rats that died = N No. of male rats = 40% of R = 0.4R Death rate of male rats = 0.3N/0.4R Death rate of female rats = 0.7N/0.6R Therefore, ratio of the death rate among the male rats to the death rate among the female rats = ...” October 22, 2012 Anurag@Gurome posted a reply to Fraction in the Problem Solving forum “Let x be the fraction of the capacity of each bottle, which is to be filled. Then 2x + 4x = 4 6x = 4 x = 2/3 So, each bottle is to be filled to 2/3 of its capacity. Hence, the 4-cup bottle should be filled with 4 * (2/3) = 8/3 cups. The correct answer is D.” October 22, 2012 Anurag@Gurome posted a reply to The profit from sale in the Data Sufficiency forum “(1) For 200,000 units, the profit exceeded$2 million So, for 380,000 units, the profit exceeded (380,000 * 2)/200,000 = $3.8 million, but it is not clear if the profit exceeded$4 million or not; NOT sufficient. (2) For 350,000 units, the profit exceeded $5 million. So, for 380,000 units, ...” October 20, 2012 Anurag@Gurome posted a reply to OG QR 2nd Ed. #169 in the Problem Solving forum “You picked 144 as the value of n², right? This means that n = 12. But the largest possible integer that divides n is 12. 48 is not possible. I hope you get the point?” October 19, 2012 Anurag@Gurome posted a reply to 12th edition OG problem. in the Problem Solving forum “Reading of n+1 corresponds to an intensity that is 10 times the intesity corresponding to a reading of n means every number on the scale is 10 times the previous number. So, we can say that f(n + 1) = 10 * f(n) Let us assume that the intensity corresponding to a reading of 3 be X, then f(3) = X ...” October 19, 2012 Anurag@Gurome posted a reply to Number properties. in the Data Sufficiency forum “Statement 1: The sum of all the numbers in the list is 60. We can have different set of 15 numbers such that their sum is 60; NOT sufficient. Statement 2: The sum of any 3 numbers in the list is 12. This is only possible when all the numbers in the set are equal. Consider the case when we ...” October 19, 2012 Anurag@Gurome posted a reply to OG problem. in the Data Sufficiency forum “Let the no. of people who were served single scoop of ice cream = S and the no. of people who were served double scoop of ice cream = D (1) At the picnic, 60 percent of the guests were served a double scoop of ice-cream. Then S : D = 40 : 60 = 2 : 3, but using this we cannot find the value ...” October 19, 2012 Anurag@Gurome posted a reply to what exactly ask?? in the Problem Solving forum “Already replied: http://www.beatthegmat.com/what-exactly-ask-t125358.html” October 19, 2012 Anurag@Gurome posted a reply to what exactly ask?? in the Problem Solving forum “"a and b are consecutive even integers in ascending order" implies b = a + 2 We have to find the value of a + (a + 2). "Sum of the two consecutive even integers that immediately precede a is 26" implies (a - 4) + (a - 2) = 26 When solved, we get, 2a - 6 = 26 or 2a = 26 + ...” October 19, 2012 Anurag@Gurome posted a reply to Reminders PRoblem in the Data Sufficiency forum “We know that remainder is always non-negative integer less than the divisor, 0 ≤ r < d. Here divisor = 7, so 0 ≤ r < 7 So, when any integer is divided by 7, then remainder can be 0, 1, 2, 3, 4, 5, or 6, which means 7 values in all. (1) The range of the seven reminders is 6. If 7 ...” October 19, 2012 Anurag@Gurome posted a reply to Word Problem in the Problem Solving forum “We can also solve it like this: Population of each district = 132000/11 = 12000 Let the least populated district have a population of 10,000. Then, 10% greater than 10,000 = (0.10 * 10,000) + 10,000 = 1,000 + 10,000 = 11,000 With one district with 10,000 and other districts greater than ...” October 19, 2012 Anurag@Gurome posted a reply to Factors in the Data Sufficiency forum “Question is: Is a^k a factor of b^m? Or Is a^k * N = b^m for any integer N, which implies N = b^m/a^k So, the question is asking if N is an integer greater than 0? (1) a is a factor of b implies a * P = b implies N = (a^m)(P^m)/(a^k) implies N = a^(m - k) * (y^m) If m < k, and a is not a ...” October 19, 2012 Anurag@Gurome posted a reply to Word Problem in the Problem Solving forum “Algebraic Approach: Let us assume that the minimum possible population = x Then the maximum population = x + 10% of x = 1.1x For x to be minimum, only one district should have minimum possible population, while the other 10 districts should have the same population, which is equal to 1.1x ...” October 19, 2012 Anurag@Gurome posted a reply to Geometry (sort of) in the Problem Solving forum “Hello! This questions has been discussed many times. See the following figures: http://s2.postimage.org/1h4h7etgk/Circle_and_triangle.jpg Hence, correct answer is E.” October 19, 2012 Anurag@Gurome posted a reply to Probability in the Data Sufficiency forum “Let us assume that, total number of Students = T Number of juniors = J Number of seniors = T - J We have to find the value of T. (1) If one student is to be chosen at random from the class to attend a conference, the probability that the student chosen will be a senior is 4/7. Total ...” October 19, 2012 Anurag@Gurome posted a reply to Coordinate geometry in the Data Sufficiency forum “Statement 1: |xy| + x|y| + |x|y + xy > 0 As |xy| + x|y| + |x|y + xy > 0 -> |x||y| + x|y| + |x|y + xy > 0 -> |y|*(|x| +x) + y*(|x| + x) > 0 -> (|x| + x)*(|y| + y) > 0 This means (|x| + x) and (|y| + y) are of same sign and none of them is equal to zero. Now, the ...” October 19, 2012 Anurag@Gurome posted a reply to Multiples and Factors in the Problem Solving forum “It is given that n! = 990 * a, for some integer a. Then n! = 2 * 3² * 5 * 11 * a, which implies that n! should have all factors of 990 so that all factors are multiples of 990. So, it should have 11 also, which means the least value of n is 11. The correct answer is B.” October 17, 2012 Anurag@Gurome posted a reply to Divisibility in the Data Sufficiency forum “consider 1st option: (x+3)/3 = k(integer) x = 3*(k - 1) if k = odd (2m+1), it is divisible by 6 if k = even (2m), it is not divisible by 6. consider 2nd option: x + 3 = odd even + odd = odd -> x is even = 2p x can be 4 , 6, 8, 10, 12. hence, cant be answered with option B alone. ...” October 17, 2012 Anurag@Gurome posted a reply to Geometry Problem in the Problem Solving forum “Let the sides of triangle be x, x, and sqrt2*x. 2x + sqrt2*x = 16+16*sqrt2. x(2 + sqrt2) = 8*sqrt2(2 + sqrt2). x = 8*sqrt2. Hypotenuse is x* sqrt2 = 8*sqrt2*sqrt2 = 16 The correct answer is B.” October 17, 2012 Anurag@Gurome posted a reply to Fractions in the Problem Solving forum “Say, the fraction of monthly take home pay Alice saved each month = x and the fraction of monthly take home pay Alice did not saved each month = y Thus, (x + y) = 1 Now, the total amount she saved at the end of the year = 3 times the amount of that portion of her monthly take home that she ...” October 15, 2012 Anurag@Gurome posted a reply to Average Problem in the Data Sufficiency forum “Let the average salary of managers of the task force = S(m), the average salary of the directors on the task force = S(d), and the average salary of all the employee on the task force = S(e). Let the no. of managers = m and no. of directors = d. We have to find d/(m + d). (1) S(m) = S(e) - ...” October 15, 2012 Anurag@Gurome posted a reply to Sets Problem in the Data Sufficiency forum “Given: Number of Japanese students ≥ 100 Let us assume that the no. of students who study Japanese = J and no. of students who study French = F Number of students who study J and F, both = 4% of F = 0.04F Question is: Is F > J? (1) 16 students study both Japanese and French implies ...” October 15, 2012 Anurag@Gurome posted a reply to DS in the Data Sufficiency forum “(1) Type J returns$115 per $1,000 invested for any one-year period and type K returns$300 per $2,500 invested for anyone-year period. From here we can find the rates for both the investments and then we can find which has a higher rate of return; SUFFICIENT. (2) The annual rate of return for ...” October 15, 2012 Anurag@Gurome posted a reply to 4^17 - 2^28 Greatest Prime Factor in the Problem Solving forum “2^34 - 2^28 = (2^28 * 2^6) - 2^28 Now, it can be seen that 2^28 is common in both the expressions above. So, this can be simplified as 2^28(2^6 - 1) = 2^28(64 - 1) = 2^28(63) I hope this helps.” October 15, 2012 Anurag@Gurome posted a reply to Coordinate Geometry and Surface area ! in the Problem Solving forum “Equation of line is y = mx + b We have to find the value of y-intercept, which means when x = 0, y = b (1) The slope is 3 times its y intercept implies m = 3b, but from here we cannot find y-intercept; NOT sufficient. (2) The x-intercept of line L is -1/3 implies when y = 0, x = -b/m = -1/3 ...” October 14, 2012 Anurag@Gurome posted a reply to Probability doubt. in the Problem Solving forum “When we count the odds of A, and independently counting the odds of A means any time A and B both happen, which means we are counting two times. Therefore, the odds of at least one of A and B occurring is p + q - pq - subtracting the overlap. In this question, we subtract the overlap, pq, ...” October 14, 2012 Anurag@Gurome posted a reply to OG13 DS 133 in the Data Sufficiency forum “Let us assume that x = abc, y = def, and z = pqr x = y + z implies abc = def + pqr Hundreds digit of x = a and hundreds digit of y and z are d and p respectively We have to find if a = d + p or not. (1) The tens digit of x is equal to the sum of the tens digits of y and z. Tens digit of x = ...” October 14, 2012 Anurag@Gurome posted a reply to Manhattan in the Problem Solving forum “Greatest Common Divisor (GCD) of 35x and 20y should be a divisor of both 35x and 20y. This implies 35x/GCD and 20y/GCD should be an integer. Now let us look at each of the answer choices: (A) 5 If x = y = 1, then 35x = 35 and 20y = 20. So, GCD of 35 and 20 = 5. Here 5 is the GCD of both 35x ...” October 14, 2012 Anurag@Gurome posted a reply to Coordinate Geometry and Surface area ! in the Problem Solving forum “The length of one piece = 2(pi)r and the other is a square. Let us assume that each side of the square is "a". Perimeter of square = 4a Now, 2(pi)r + 4a = 40 4a = 40 - 2(pi)r a = (pi)r² + (10 - (pi)r/2)² The correct answer is (pi)r² + (10 - (pi)r/2)².” October 14, 2012 Anurag@Gurome posted a reply to Points Earned in the Problem Solving forum “As 1 ≤ n ≤ 5, points are only awarded for 1st, 2nd, 3rd, 4th, and 5th place. Hence, the points that can be earned are 1, 2, 3, 4, and 5. Therefore, total points can be earned = (1 + 2 + 3 + 4 + 5) = 15 As there were no ties, disqualifications or withdrawals, no same point are awarded to more ...” October 14, 2012 Anurag@Gurome posted a reply to QUADRATIC EQUATIONS in the Problem Solving forum “I am assuming the question is 3/(x + 3) + 4/(x + 4) = 2/(x + 2) + 5/(x + 5) In case the answer choices were given to us, then we would have plugged the value to find which value of x satisfies the given equation, but since the answer choices are not known so we can solve this by the method ...” October 14, 2012 Anurag@Gurome posted a reply to Probability doubt. in the Problem Solving forum “Probability that exactly one of the events A and B occurs means if A occurs then B does not occur or if B occurs then A does not occur. Therefore, p * (1 - q) + q * (1 - p) = p - pq + q - pq = p + q - 2pq The correct answer is D.” October 14, 2012 Anurag@Gurome posted a reply to GMATPrep 1 Rate Problem in the Problem Solving forum “Total distance 50 * 5 = 250 miles Gas consumed = 250/30 = 25/3 gallons Fraction of gas = (25/3)/12 = 25/36 The correct answer is E.” October 14, 2012 Anurag@Gurome posted a reply to GMATPrep 1 Geometry Question in the Problem Solving forum “As triangle ABC is equilateral, arc ABC is 2/3 of the circumference of the circle. Hence, circumference of the circle = 24*3/2 = 36 Hence, diameter of the circle = 36/π = Slightly less than 36/3 ≈ 11 The correct answer is C.” October 14, 2012 Anurag@Gurome posted a reply to Manhattan in the Data Sufficiency forum “(A) -2^n is always negative for all values of n, while (-2)^-n is positive for even values and negative for odd integers. If n = 0, then -2^n = -1 and (-2)^0 = 1, so for n = 0, it does not hold true. If n = 1, then -2^n = -2 and (-2)^-n = -1/2, so -2^n is not equal to (-2)^-n and if n = 2, then ...” October 14, 2012 Anurag@Gurome posted a reply to GMATPrep 1- Digits in the Data Sufficiency forum “Let us assume that z = a.bcd. Here we can see that the hundredths digit of z is c. We have to find the value of c. (1) The tenths digit of 10z is 2 implies 10z = 10 * a.bcd = ab.cd The tenths digit of 10z is c. So c = 2; SUFFICIENT. (2) The units digit of 1,000z is 2 implies 1000z = 1000 * ...” October 14, 2012 Anurag@Gurome posted a reply to Manhattan in the Data Sufficiency forum “Distance between the point A (x,y) and the origin can be found by the formula: D = √(x² + y²) We have to find if √(a² + b²) = √(c² + d²) OR (a² + b²) = (c² + d²) (1) a/b = c/d implies a = cx and b = dx for some integer so that x is not zero; NOT sufficient. (2) √(a²) + ...” October 14, 2012 Anurag@Gurome posted a reply to Difficult Problem in the Data Sufficiency forum “Let us assume that the total no. of hours to complete the job = T (1) r + 0.2r * (T - 4) = 288 But we do not know that value of r, so we cannot find T; NOT sufficient. (2) r + 0.2r * (T - 4) = 2.4r 0.2T = 2.2 implies T = 11; SUFFICIENT. The correct answer is B.” October 14, 2012 Anurag@Gurome posted a reply to Geometry in the Data Sufficiency forum “Question is:$10,000 is deposited in a certain account that pays r percent annual interest compounded annually, the amount D(t), in dollars, that the deposit will grow to in t years is given by D(t) = 10,000 {1+(r/100)}^t. What amount will the deposit grow to in 3 years? (1) D(t) = 11,000 (2) ...”
October 14, 2012
Anurag@Gurome posted a reply to Geometry in the Data Sufficiency forum
“Sum of interior angels of a quadrilateral is 360 degrees. (1) Two of the interior angles of ABCD are right angles implies the angles can be 90 + 90 + the remaining two angles that sum up 180. No definite answer; NOT sufficient. (2) The degree measure of angle ABC is twice the degree ...”
October 14, 2012
Anurag@Gurome posted a reply to Order of operation in the Problem Solving forum
“6/2(1 + 2) = 6/2(3) = 6/6 = 1 The correct answer is (a).”
October 14, 2012
Anurag@Gurome posted a reply to distance-time and prime factor in the Problem Solving forum
“h(100) = 2 * 4 * 6 * ... * 100 = (2 * 1) * (2 * 2) * (2 * 3) * ... * (2 * 50) = 2^(50) * (1 * 2 * 3 ... * 50) Then h(100) + 1 = 2^(50) * (1 * 2 * 3 ... * 50) + 1 Now, h(100) + 1 cannot have any prime factors 50 or below, because dividing this value by any of these prime numbers will give a ...”
October 13, 2012
Anurag@Gurome posted a reply to distance-time and prime factor in the Problem Solving forum
“Time taken to travel upstream = 90/(v - 3) hr Time taken to travel downstream = 90/(v + 3) hr Traveling upstream took 1/2hr more than downstream. So, 90/(v - 3) = 90/(v + 3) + 1/2 180(v + 3) = 180(v - 3) + (v² - 9) 1080 = v² - 9 or v = √1089 = 33 Speed for downstream = 33 + 3 = ...”
October 13, 2012
Anurag@Gurome posted a reply to OG 12 | VICs in the Data Sufficiency forum
“If w > 10, min(10, w) = 10 If w < 10, min(10, w) = w Statement 1: w = max(20, z) This means w is maximum of 20 and z. Hence, w is more than or equal to 20. Therefore, w > 10 --> min(10, w) = 10 Sufficient Statement 2: w = max(10, w) This means w is maximum of 10 and ...”
October 11, 2012
Anurag@Gurome posted a reply to set of different flowers - probability in the Data Sufficiency forum
“Probability that the florist does not have to change the bouquet = 1 - (probability that the two flowers are azaleas + probability that the two flowers are buttercups + probability that the two flowers are petunias) = 1 - 13/18”
October 9, 2012
Anurag@Gurome posted a reply to Help requested in the Problem Solving forum
“Explanation to Q2: 2x - 3y ≤ -6 implies y ≥ (2x/3) + 2 Let us draw the above line in the coordinate system. Let us write the line in the form, x/A + y/B = 1. So, the line is x/(-3) + y/2 = 1 http://s17.postimage.org/hr9vq4q0b/Intercept.jpg It can be seen that the mentioned area is ...”
October 8, 2012
Anurag@Gurome posted a reply to Help requested in the Problem Solving forum
“Explanation to Q1: Let the actual ratio be 3N : 4N When both the numerator and denominator are increased by 5, then ratio becomes (3N + 5) : (4N + 5) Until we know the value of N, we can not determine the actual ratio. The correct answer is E.”
October 8, 2012
Anurag@Gurome posted a reply to GMAT PREP PS Problem in the Problem Solving forum
“Let the envelopes be E1, E2, E3, E4 and the corresponding letters be l1, l2, l3, l4. Suppose l1 goes to E1 and the other letters do not go in their corresponding envelopes. So, E2 will have either l3 or l4 If E2 has l3, E3 will have l4, E4 will have l2. If E2 has l4, E3 will have l2, E4 will ...”
October 8, 2012
Anurag@Gurome posted a reply to MGMAT Combination Problem in the Data Sufficiency forum
“Let us assume that number of $10,000 scholarships = A, Number of$5,000 scholarships = B, Number of $1,000 scholarships = C, and Total number of scholarships granted = T Then T = A + B + C Number of different ways the committee can distribute scholarships among the pool of 10 applicants = ...” October 8, 2012 Anurag@Gurome posted a reply to OG 12| Statistics in the Data Sufficiency forum “Statement 1: The sum of all the numbers in the list is 60. We can have different set of 15 numbers such that their sum is 60; NOT sufficient. Statement 2: The sum of any 3 numbers in the list is 12. This is only possible when all the numbers in the set are equal. Consider the case when we ...” October 8, 2012 Anurag@Gurome posted a reply to PS | Mixtures | OG 12 in the Data Sufficiency forum “Given: S : A : W = 2 : 50 : 100 The ratio of soap to alcohol is doubled implies S : A = 2 * (2/50) = 4/50 The ratio of soap to water is halved implies S : W = (1/2) * (2/100) = 1/100 or 4/400 Therefore, new ratio of S : A : W = 4 : 50 : 400 implies A : W = 50 : 400 If A = 2 * 50 = 100, then W ...” October 8, 2012 Anurag@Gurome posted a reply to OG 12 | Algebric translations in the Data Sufficiency forum “(1) The bucket currently contains 9 liters of water but we do not know the maximum volume of bucket; NOT sufficient. (2) If 3 liters of water are added to the bucket when it is half full of water, the amount of water in the bucket will increase by 1/3. Let V be the total volume of the bucket. ...” October 8, 2012 Anurag@Gurome posted a reply to PS | OG 12 | Combinatorics in the Data Sufficiency forum “http://s14.postimage.org/dfer14zjx/Pat.jpg For the length to be minimum, Pat should eight go upwards or right. So, for this he goes 3 steps up and then 2 steps right or 2 steps right and then 3 steps up, which makes 5 steps in all. So, number of routes from X to Y that Pat can take having the ...” October 8, 2012 Anurag@Gurome posted a reply to OG12 Question 122, OG13 Question 130. in the Data Sufficiency forum “In a rectangular solid, there are 6 faces let’s say A, B, C, D, E and F from among which we can have 3 pairs such that two faces of each pair will have the same area and will be opposite. For example A and D will be opposite and have the same area. B and E will be opposite and have the same ...” October 8, 2012 Anurag@Gurome posted a reply to Averages in the Problem Solving forum “Assuming that the savings is 10 moolahs per month. By hoola Boola Moola(hbm) way of calculating: monthly avg savings based on hbm way = 10 Annual Expenditure = 288 monthly Expenditure based on hbm way = 288/9 = 32 avg monthly income based on hbm way = avg Expenditure + avg Savings = 32 + 10 ...” October 5, 2012 Anurag@Gurome posted a reply to Please help me with this problem in the Problem Solving forum “Number of video game cartridges owned by Bradley = b Number of video game cartridges owned by Andrew = 3b Number of video game cartridges owned by Charlie = b/4 Hence, total = (b + 3b + b/4) = 17b/4 The correct answer is B.” October 5, 2012 Anurag@Gurome posted a reply to positive integer n in the Data Sufficiency forum “Statement 1: Implies the product of any (n + 1) consecutive positive integers is divisible by 16. Now the product of any 6 or more consecutive integers is always divisible by 16. Hence, (n + 1) ≥ 6 => n ≥ 5 Not sufficient Statement 2: n² - 9n + 20 = 0 => (n - 4)(n - 5) = 0 Hence, ...” October 5, 2012 Anurag@Gurome posted a reply to OG 12 | WORD PROBLEMS in the Data Sufficiency forum “Let the time needed for car X to travel across the bridge be Tx seconds and the time for Y be Ty seconds. We have to find Tx. (1) Car X drove onto the bridge exactly 3 seconds after car Y drove onto the bridge and drove off the bridge exactly 2 seconds after car Y drove off the bridge. Car X ...” October 5, 2012 Anurag@Gurome posted a reply to Functions again! in the Data Sufficiency forum “For the function f(x) = y = to intersect with the x - axis, y should be 0. => ax^2 + c = 0 x^2 = -c/a so we will have real roots if x^2 is positive or zero. 1) a < 0 x^2 = -c/a, x^2 is positive when c is +ve if c is -ve, we will have imaginary roots. so cant answer with option 1 ...” October 3, 2012 Anurag@Gurome posted a reply to GMATPrep 1 in the Problem Solving forum “If n is multiple of 5, and n = p²q where p and q are prime, then either p or q or both of them must be equal to 5. Let''s analyze each of the cases. (Note that only one of the following can happen at a time) 1. p = 5, p² is multiple of 25, q² not 2. q = 5, q² is multiple of 25, p² not 3. ...” October 1, 2012 Anurag@Gurome posted a reply to DS Geometry in the Data Sufficiency forum “When the graph intersects the x-axis, the intersection point will be (x, 0). This implies (x + a)(x + b) = 0 or x^2 + (a + b)x + ab = 0. (1) a + b = -1 does not gives us the values of a and b. So, (1) is NOT SUFFICIENT. (2) When the graph intersects the y-axis, the intersection point is ...” October 1, 2012 aneesh.kg posted a reply to Compound interest in the Problem Solving forum “In the formula Final Amount = P(1 + R/100)^n R = 12.5 n = 3 because the principal will be compounded thrice. 1458 = P(1 + 12.5/100)^3 1458 = P(9/8)^3 P = 1458 (8/9)^3 P = 2 (8)^3 = 2^10 = 1024 (A) is correct.” September 29, 2012 Anurag@Gurome posted a reply to which of the following sentence is correct in the Sentence Correction forum “anyone = one among a non specified group =>any one = one among a specified group So B is better.” September 28, 2012 Anurag@Gurome posted a reply to Slope in the Data Sufficiency forum “Equation of a line in point intercept form is y = mx + b, where m is the slope of the line and b is the y-intercept of the line, (-b/m) is the x-intercept of the line. We are given two lines: y(m) = mx + b and y(n) = nx + c. They intersect at the point (-2, 4). So, 4 = -2m + b and 4 = -2n + c b ...” September 28, 2012 Anurag@Gurome posted a reply to lines r & s in the Data Sufficiency forum “Let the equation of line r be y = m1x+c1, where m1 is the slope and c1 is the y intercept. Let the equation of line s be y = m2x+c2, where m2 is the slope and c2 is the y intercept. We need to know whether c1 < c2 or not. Statement 1: At the intersection point x = (c2 - c1)/(m1-m2), y = ...” September 28, 2012 Anurag@Gurome posted a reply to number properties problem in the Data Sufficiency forum “The question can be rephrased as "If 3 < m < 13 < n, is n/m an integer?" (1) The information in statement 1 implies that 3n/m is an integer. Now we have find whether n/m is an integer. Given that 3 < m < 13 < n, if n = 36 and m = 6, then n/m is an integer. On the ...” September 28, 2012 Anurag@Gurome posted a reply to Geometry | OG 12 in the Problem Solving forum “Volume of cylinder = (pi) * radius² * height of cylinder If the cylinder is placed on 6 in by 8 in. face, then it''s maximum radius is 6/2 = 3 and volume will be (pi) * 3² * 10 = 90(pi) If the cylinder is placed on 6 in by 10 in. face, then it''s maximum radius is 6/2 = 3 and volume will be ...” September 27, 2012 Anurag@Gurome posted a reply to Geometry | Og 12 in the Problem Solving forum “http://s13.postimage.org/nhxhi0ieb/axes.jpg The line y = x is the perpendicular bisector of segment AB, so the point B is the mirror reflection of point A around the line y = x, so its coordinates are (3, 2). In the same way, since the x-axis is the perpendicular bisector of segment BC then the ...” September 27, 2012 Anurag@Gurome posted a reply to Geometry | OG12 in the Problem Solving forum “It can be seen that the graph is symmetric with respect to line x = 2, so the value of y when x = 3 will be the same as the value of y when x = 1, so y = 1. The correct answer is E.” September 27, 2012 Anurag@Gurome posted a reply to Geometry | OG12 in the Data Sufficiency forum “(1) 3r + 2s = 6 may or may not lie in region R. So, (1) is NOT SUFFICIENT to answer the question. (2) If we take r = 3 and s = 2, then the point (3, 2) does not lie in region R. r ≤ 3 and s ≤ 2 implies we can also take negative values for r and s. If r = -2, s = -3, then (-2, -3) lies in ...” September 27, 2012 Anurag@Gurome posted a reply to problem solving - combinations + probability in the Problem Solving forum “Check the answer choices please, it should be "3" instead of "2" in the denominator. Probability of getting a 5 = 1/6 Probability of getting a 6 = 1/6 Probability of getting a 5 or 6 = 1/6 + 1/6 = 1/3 Now, probability of getting 1, 2, 3, or 4 = 1 - probability of getting ...” September 27, 2012 Anurag@Gurome posted a reply to xy-plane, in the Data Sufficiency forum “We can get the equation of line with slope and a point on the line. So as slope is given in the question, and in the options we have a point on the line. we will get the equation of the lines in both cases. m = 3/2, y = mx +c, we need to substitute the point co-ordinates to get the c. once we ...” September 26, 2012 Anurag@Gurome posted a reply to Distance travelled in the Data Sufficiency forum “http://s17.postimage.org/ycrnno157/car_X.jpg (1) Car X arrives in Town B 90 minutes after leaving city A, but nothing has been said about car Y; NOT sufficient. (2) Car Y arrives in Town A at the same time Car X arrived in Town B. Since car Y starts 15 min after car X, so car X needs 15 min ...” September 26, 2012 Anurag@Gurome posted a reply to probability of red and ace ??? in the Problem Solving forum “Its been long time i played cards. i was thinking of Red diamonds. Yeah the probability for a red is 1/2. i will edit the ans.” September 26, 2012 Anurag@Gurome posted a reply to probability of red and ace ??? in the Problem Solving forum “When replaced: probability of the 1st card to be red = 1/2 when we replaced, we will have the same set of cards probability for an ace = 4/52 probability of both events to happen = 1/2 * 4/52 = 1/26 when not replaced: probability of the 1st card to be red = 26/52 but the 1st card can be red ...” September 26, 2012 Anurag@Gurome posted a reply to Problem solving in the Problem Solving forum “h(100) = 2 * 4 * 6 * ... * 100 = (2 * 1) * (2 * 2) * (2 * 3) * ... * (2 * 50) = 2^(50) * (1 * 2 * 3 ... * 50) Then h(100) + 1 = 2^(50) * (1 * 2 * 3 ... * 50) + 1 Now, h(100) + 1 cannot have any prime factors 50 or below, because dividing this value by any of these prime numbers will give a ...” September 24, 2012 Anurag@Gurome posted a reply to Factor question in the Problem Solving forum “36² = 2^4 * 3^4 So, no. of factors = power of each prime factor + 1 = (4 + 1)(4 + 1) = 25 The correct answer is D.” September 24, 2012 Anurag@Gurome posted a reply to Top Health IT focus Global MBA/ Masters programs in the Research MBA Programs forum “This is as good a list as any. I would suggest that you speak with alumni of your target schools (specially alumni that focused on Healthcare IT) to short list further. I would also look at other admissions parameters that can help you select additional schools in regions that have high healthcare ...” September 22, 2012 Anurag@Gurome posted a reply to Log shipment X & Y in the Data Sufficiency forum “For the median, we need to know the center most length when arranged in order. given: Of the 13 logs in shipment X arranged in order, 7th log length is 84 inches x1, x2, x3, x4, x5, x6, 84, y1, y2, y3, y4, y5, y6 of the 21 logs in shipment Y arranged in order, 11th log length is 85 inches ...” September 22, 2012 Anurag@Gurome posted a reply to Clarification about modifiers in the Sentence Correction forum “Incidentally, The serial comma is frowned upon in Queen''s English. For a humorous reference to the battle with commas, read the preface of the book "Eats, Shoot & Leaves" by Lynne Truss. In that preface, the author talks about her struggle with an editor who loved commas (whereas the ...” September 22, 2012 Anurag@Gurome posted a reply to Independent clause, FANBOYS Independent clause in the Sentence Correction forum “If you do not have two subjects and two verbs separated by the FANBOYS, you do not need to insert the comma before the FANBOYS. In other words, if the second grouping of words isn’t a complete thought, don’t use a comma. Try reading the words after FANBOYS all by themselves. Do they make a ...” September 22, 2012 Anurag@Gurome posted a reply to confusing DS in the Data Sufficiency forum “You are welcome.” September 21, 2012 Anurag@Gurome posted a reply to inequalities in ds in the Data Sufficiency forum “Statement 1: 5^(k + 1) > 3000 --> (5^k)*5 > 3000 --> 5^k > 600 Now 5^k can be more than or less than 1000. Not sufficient Statement 2: 5^(k - 1) = 5^k - 500 --> 5^k/5 = 5^k - 500 --> 5^k = 5*5^k - 2500 --> 4*5^k = 2500 --> 5^k = 625 < 1000 ...” September 21, 2012 Anurag@Gurome posted a reply to confusing DS in the Data Sufficiency forum “If w > 10, min(10, w) = 10 If w < 10, min(10, w) = w Statement 1: w = max(20, z) This means w is maximum of 20 and z. Hence, w is more than or equal to 20. Therefore, w > 10 --> min(10, w) = 10 Sufficient Statement 2: w = max(10, w) This means w is maximum of 10 and ...” September 21, 2012 Anurag@Gurome posted a reply to Combination? in the Data Sufficiency forum “No. of possible ways of choosing 2 lightbulbs from a box of 12 lightbulbs = 12C2 = 12!/(2!)(12 - 2)! = 12!/(2!)(10!) = (12 * 11)/2 = 6 * 11 = 66 The correct answer is D.” September 21, 2012 Anurag@Gurome posted a reply to GMAT Prep Practice Test - Confusing DS in the Data Sufficiency forum “Statement 1: (x + y) < 20 Possible combinations, 1. x = 25, y = -10 2. x = 10, y = 5 Not sufficient Statement 2: No information regarding y. Not sufficient 1 & 2 Together: Same examples as in statement 1. Not sufficient The correct answer is E.” September 21, 2012 Anurag@Gurome posted a reply to divisible by 7? in the Data Sufficiency forum “consider 1st option: The product of abc is divisible by 3, but only c is divisible by 21. The product of abc is divisible by 3 => atleast one of the a,b,c is a multiple of 3. but only C is divisible by 21 => c is a multiple of 3 and 7. for a and b not to be divisible by 21 (7*3) they ...” September 20, 2012 Anurag@Gurome posted a reply to must be true in the Problem Solving forum “x² = xy implies x² - xy = 0 implies x(x - y) = 0, which means either x = 0 or x = y. But it is given that x and y are different integers, so x = y cannot be true. Hence, x = 0 holds true. The correct answer is A.” September 19, 2012 Anurag@Gurome posted a reply to cylinders? in the Problem Solving forum “Volume of can X = (pi)r²h, which when filled to capacity sells for$2. Volume of can Y = (pi)(2r)²(2h) = 8(pi)r²h Can Y is only half filled, so volume of oil in it = 4(pi)r²h Now (pi)r²h is sold for $2 Hence, 4(pi)r²h will be sold for 4 *$2 = $8 The correct answer is E.” September 19, 2012 Anurag@Gurome posted a reply to length in the Problem Solving forum “To maximize the length of an integer less then 1,000, we should minimize its prime bases. Minimum prime base = 2 So, 2^x < 1,000 or x < 10 Maximum length = 9 for 2^9 = 512 Also, note that 2^9 is not the only integer whose length is 9, for example 2^8 * 3 = 768 < 100 also has the ...” September 19, 2012 Anurag@Gurome posted a reply to Coordinate Geometry and Probability in the Problem Solving forum “http://s16.postimage.org/pzfkxdlld/pic1.jpg the point in the triangle with y < x will be the triangle formed with y = x with our triangle and which is shaded brown in the figure. we need to get the point on the line formed by (0,10) and (5,0) where y = x meets. the equation of the line formed ...” September 17, 2012 Anurag@Gurome posted a reply to internal review in the Problem Solving forum “another way of doing this is: you need to have one selection (jack, jill) out of number of selections possible of 2 people in 6 people group number of ways of selecting two people in 6 people = 6C2 jack and jill selection constitutes of 1 selection. so the probability of selecting jack and ...” September 17, 2012 Anurag@Gurome posted a reply to internal review in the Problem Solving forum “Jack and Jill work at a hospital with 4 other workers, so there are 6 workers. out of the 6, 2 to be chosen. the probability of both jack and jill be chosen = the probability of jack chosen first and jill chosen next + the probability of jill chosen first and jack chosen next the probability ...” September 17, 2012 Anurag@Gurome posted a reply to p divisible by 9? in the Data Sufficiency forum “(1) p/10 + q/10 is an integer. If p = 10, q = 20, then p/10 + q/10 = 10/10 + 20/10 = 30/10 = 3, which is an integer. Here p is not divisible by 9. If p = 90, q = 20, then p/10 + q/10 = 90/10 + 20/10 = 110/10 = 11, which is an integer. Here p is divisible by 9. No definite answer; NOT sufficient. ...” September 17, 2012 Anurag@Gurome posted a reply to isosceles triangle in the Data Sufficiency forum “From given we can say that the sides of triangle can be: 6, 6, 6 square root 3 or 6 square root 3, 6 square root 3, 6 consider option 1: one of the angles is obtuse. so it is not our equal angles, as there cannot be two obtuse angles in a triangle. the side opposite to the larger angle is the ...” September 17, 2012 Anurag@Gurome posted a reply to If a committee of 4 people is to be selected from among 6 ma in the Problem Solving forum “yes, you are right. The answers look good.” September 14, 2012 Anurag@Gurome posted a reply to Number Properties in the Problem Solving forum “modulus value is always non-negative. |x-4| >= 0 so 4 - x >= 0 -> x =< 4 for x =< 4, |x-4| = 4-x” September 14, 2012 Anurag@Gurome posted a reply to If a committee of 4 people is to be selected from among 6 ma in the Problem Solving forum “lets take the couples be (x1,y1)....(x6,y6) In the numerator 12*1*10*1 lets take the 1st time you have chosen x1. so y1 will be chosen. the next time you have chosen x2. so y2 will be chosen. what have you chosen is x1,y1,x2,y2 now you have chosen 1st time y1. so you are choosing x1. the ...” September 14, 2012 Anurag@Gurome posted a reply to If a committee of 4 people is to be selected from among 6 ma in the Problem Solving forum “This means 1 couple and 2 non-couple people. for selecting 1 couple we have 6C1 options. as we have selected 1 couple already, there are 5 couples left. in these 5 couples we need to have 2 couples to select and 1 person from each couple. so it will be 5C2 * 2 * 2. ans = 6c1 * 5c2 * 2 * 2 = ...” September 14, 2012 Anurag@Gurome posted a reply to Question of number properties in the Data Sufficiency forum “(1) √n is an odd integer implies that n must also be an odd integer. Example: √49 = 7, √9 = 3, √121 = 11, but √100 = 10, √64 = 8 Also, all the powers of an odd integer are also odd, viz., 3² = 9, 3^3 = 27, 3^4 = 81 and so on. It is given that n represents the number of different ...” September 13, 2012 Anurag@Gurome posted a reply to Possible values for n in the Problem Solving forum “777 = q * n + 77, where n > 77 qn = 700 = 7 * 2² * 5² Now since n must be more than 77, so n could take only 5 values: 100, 140, 175, 350, and 700. The correct answer is D.” September 13, 2012 Anurag@Gurome posted a reply to Too many tables, too many members! in the Problem Solving forum “See the post here: http://www.beatthegmat.com/club-members-t116276.html” September 13, 2012 aneesh.kg posted a reply to 770 (Q50,V47): How BEATtheGMAT helped me beat the GMAT!! in the I just Beat The GMAT! forum “I logged into BTG after a long time and remembered that you were going to attempt GMAT in August. Congratulations EagleEye, 770! Not surprised at all. A 750 would''ve surprised me. Please keep posting on BTG; your posts do help people a lot. Good luck for the Admissions process :)” September 12, 2012 Anurag@Gurome posted a reply to Brine solution in the Problem Solving forum “The amount of salt in 10gallons of 10% brine solution = 1 gallon we are adding only water so that the concentration becomes 7%. the concentration after adding x gallons of water = 1 gallon / (10 gallons + x gallons) = 7 /100 => x =30/7 = 4.28 hence, it is C” September 12, 2012 Anurag@Gurome posted a reply to veritas question in the Data Sufficiency forum “(1) 2xy < 100 If x = y = 0, then x² + y² = 0 < 100 If x = 10, y = -10, then x² + y² = 100 + 100 = 200 > 100 No definite answer; NOT sufficient. (2) (x + y)² > 200 x² + 2xy + y² > 200 Since the square of any number is more than or equal to zero, so (x - y)² more than or ...” September 10, 2012 Anurag@Gurome posted a reply to MATH HELPPP in the Problem Solving forum “In 1 day, Anik can build 1/10 of the wall In 1 day, Kun can build 1/12 of the wall In 1 day, Arefin can build 1/15 of the wall In 1 day, (Anik + Kun + Arefin) can build 1/10 + 1/12 + 1/15 = (6 + 5 + 4)/60 = 1/4th of the wall. In 16 days, (Anik + Kun + Arefin) can build (1/4) * 16 = 4 such ...” September 10, 2012 Anurag@Gurome posted a reply to MATH HELPPP in the Problem Solving forum “Faisal, you should always post only 1 question per thread. Let the no. of people be N, and the amount of money to be divided be$P. Then amount of money taken by each = $P/N If there had been 4 more people, everyone would have got tk 16 less: No. of people = N + 4, Amount of money taken by ...” September 10, 2012 Anurag@Gurome posted a reply to Probability Data Sufficiency question in the Data Sufficiency forum “(1) The probability that the two bulbs to be drawn will be defective is 1/15. Now the probability of drawing 2 defective bulbs out of a total of 10 bulbs depends on the number of defective bulbs, n. So, we can find value of n if we are given the probability; SUFFICIENT. (2) The probability ...” September 10, 2012 Anurag@Gurome posted a reply to Is XY a multiple of 105? in the Data Sufficiency forum “As x is a multiple of 6 (= 2*3) and y is a multiple of 14 (= 2*7), xy is a multiple of 6*14 = 84. Hence, xy is a multiple of 3, 4, and 7. Now for xy to be a multiple of 105 (= 3*5*7), xy has to be a multiple of 5 also. Only statement 2 allows us to conclude that xy is a multiple of 5 too as y is ...” September 10, 2012 Anurag@Gurome posted a reply to John and Mary in the Problem Solving forum “Initially, John and Mary were each paid x dollars in advance. Mary gave John y dollars of her payment implies John has$(x + y) and Mary has $(x - y). John has worked for 10 hours, so for 1 hr he is paid$(x + y)/10 Mary worked for 8 hrs, so for 1 hr she is paid $(x - y)/8 Since their hourly ...” September 10, 2012 Anurag@Gurome posted a reply to Probability in the Problem Solving forum “Number of ways to choose 3 people out of 4 = 4C3 Number of different committees that can be chosen if two married people, both cannot serve the committee = 4C3 * 2^3 = 4 * 8 = 32 (2^3, as we can choose any 2 people from each chosen team) The correct answer is E.” September 10, 2012 Anurag@Gurome posted a reply to Averages in the Problem Solving forum “Say, the length of each red stick = L inches Hence, the average length of the sticks in Box W = MW = (L + 18) And, the average length of the sticks in Box V = MV = (L - 6) Hence, MW - MV = (L + 18) - (L - 6) = (28 + 6) = 24 The correct answer is E.” September 10, 2012 Anurag@Gurome posted a reply to MGMAT Chapter 7 word translations # 7 ( video category) in the Problem Solving forum “Let us assume that x = no. of movies classified under action, drama and comedy. http://s15.postimage.org/9tlkn8dbr/Venn_diag.jpg Action = 10 -(3 - x + 5 - x + x) = 2 + x Drama = 20 -(5 - x + x + 4 - x) = 11 + x Comedy = 18 -(4 - x + x + 3 - x) = 11 + x Therefore, 2 + x + 11 + x + 11 + x + ...” September 10, 2012 Anurag@Gurome posted a reply to What is the volume of the cube? in the Data Sufficiency forum “Let each side of the cube = s inches Then volume = s^3 (1) The surface area of the cube is 600 square inches. Surface area of cube = area of face * no. of faces So, surface area of cube = s² * 6 s² * 6 = 600 implies s² = 100 or s = 10 Hence, volume = 10^3 = 1000; SUFFICIENT. (2) The ...” September 10, 2012 Anurag@Gurome posted a reply to Geometry in the Problem Solving forum “Perimeter of rectangle = 2(L + W) Area = L * W Now, 2(L + W) = 76 L + W = 38 ... Equation (1) LW = 360 ... Equation (2) From Equations (1) and (2), L(38 - L) = 360 L² - 38L + 360 = 0 (L - 18)(L - 20) = 0 L = 18, 20 implies W = 20, 18 Therefore, length of the shortest side = 18 ...” September 8, 2012 Anurag@Gurome posted a reply to Number theory in the Problem Solving forum “Prime factorization of 4,000,000 = 2² * 1,000,000 = 2² * 10^6 = 2^8 * 5^6 = 256 * 5^6 So, 5^n > 256 * 5^6 5^4 = 625, which is greater than 256 and 5^3 = 125 < 256 So, 5^n should at least be equal to 5^4 * 5^6 = 5^10 for 5^n > 256 * 5^6 to hold true. Therefore, the least possible ...” September 8, 2012 Anurag@Gurome posted a reply to Is there a faster way? in the Problem Solving forum “I think you missed one of the dimensions: it should be 6 inches by 8 inches by 10 inches. Assuming this, we can solve it like below. Volume of cylinder = (pi) * radius² * height of cylinder If the cylinder is placed on 6 in by 8 in. face, then it''s maximum radius is 6/2 = 3 and volume will be ...” September 8, 2012 Anurag@Gurome posted a reply to Area in the Data Sufficiency forum “http://s7.postimage.org/5dzw2vqon/Rec.jpg Area of rectangle = length * width = L * W sq units (1) Diagonal = 2W So, by Pythagoras Theorem, (2W)² = L² + W² or 4W² = L² + W² or 3W² = L² but we do not know the value of L or W; NOT sufficient. (2) Length = 173 feet Area = 173 * W, but ...” September 7, 2012 Anurag@Gurome posted a reply to M=N+2 in the Data Sufficiency forum “Yes, n can be 20 and -20, both. I''ve edited my reply. The answer should be A here.” September 7, 2012 Anurag@Gurome posted a reply to cf or fg in the Data Sufficiency forum “We have to find if cf > fg or cf < fg. (1) c > g If f is a positive integer, then multiplying both sides by f gives, fc > fg If f is a negative integer, then multiplying both sides by f gives, fc < fg No definite answer; NOT sufficient. (2) f² = cg does not imply if cf > ...” September 7, 2012 Anurag@Gurome posted a reply to M=N+2 in the Data Sufficiency forum “m = n + 2 We want to find the value of m² + 4m + 4. (1) n = 20 implies m = 20 + 2 = 22 So, we can find the value of m² + 4m + 4, as we know m; SUFFICIENT. (2) n² = 400 implies n = 20, -20 If m = 22, so we can find the value of m² + 4m + 4, as we did in statement 1. If m = -18, we get a ...” September 7, 2012 Anurag@Gurome posted a reply to Data Sufficiency-if X & Y are integer in the Data Sufficiency forum “given: x, y are integers considering x^3 = -125 -> x = -5 x^7 = (-5)^7 = -ve number 6^y where y is any integer take y = -2, 6^y is positive y = 0, 6^y is positive y = 2, 6^y is positive so, x^3 is less than 6^y. it is sufficient to answer. consider y^2 = 36, -> y = +6 or -6 we ...” September 6, 2012 Anurag@Gurome posted a reply to k m p odd? in the Data Sufficiency forum “k - m - p = k - (m + p) (1) m is even and p is odd. So m + p is odd. k is even. So k - (m + p) is odd; SUFFICIENT. (2) Since k, m and p are consecutive integers, let m = k + 1 and p = k + 2. So m + p is 2k + 3. k - (m + p) is k - (2k + 3) = -k - 3. So the value of k - (m + p) ...” September 6, 2012 Anurag@Gurome posted a reply to OG12 DS Question 170 in the Data Sufficiency forum “n^3 - n = n(n² - 1) = (n - 1)n(n + 1) (1) n = 2k + 1, where k is an integer implies n = odd, and since n is odd so n - 1 and n + 1 are even. So, (n - 1)n(n + 1) is divisible by 4; SUFFICIENT. (2) n² + n is divisible by 6. If n = 2 then n^3 - n = 6, then n^3-n is NOT divisible by 4. If n = ...” September 6, 2012 Anurag@Gurome posted a reply to simple algebra question in the Problem Solving forum “It can be, if it is given that x is a positive integer. Example: If x = -2, then -2 < (-2)² or -2 < 4 is true but 1 < -2 does not hold true. I hope that helps.” September 6, 2012 Anurag@Gurome posted a reply to x+y+z in the Data Sufficiency forum “1) x - y = 6 implies x = y + 6 So, 4x = 5y implies 4(y + 6) = 5y or 4y + 24 = 5y or y = 24 5y = 10z implies 5 * 24 = 10z or z = 12 We know the values of y and z, so we can find the value of x and hence can fine the value of x + y + z; SUFFICIENT. 2) y + z = 36 implies y = 36 - z So, 5y = 10z ...” September 6, 2012 Anurag@Gurome posted a reply to Profit loss in the Problem Solving forum “Total cost = 60 * ($250/1.2) = 50 * 250 No. of cameras sold = 60 - 6 = 54 Total revenue = 54 * 250 No. of cameras returned = 6 Total refund = 6 * (250/1.2) * 0.5 Therefore, total income = 54 * 250 + 6 * (250/1.2) * 0.5 Hence, the dealer''s approximate profit = (54 * 250 + 6 * (250/1.2) * ...”
September 6, 2012
Anurag@Gurome posted a reply to xy in the Data Sufficiency forum
“(1) 2 < x < 5 but we have no info about y; NOT sufficient. (1) 6 > y but no info on x; NOT sufficient. Combining (1) and (2), 2 < x < 5 and y < 6 If x = 3, y = 1, then xy = 3. Here xy < 27 If x = 4.9, y = 5.9, then xy = 28.9 > 27 No definite answer; NOT sufficient. ...”
September 5, 2012
Anurag@Gurome posted a reply to speed in the Problem Solving forum
“When speed was 55 mph, time taken to cross 8 miles stretch = 8 * 60/55 = 8 * 12/11 = 96/11 = 8.72 mins When speed was 55 mph, time taken to cross 8 miles stretch = 8 * 60/35 = 8 * 12/7 = 13.71 Difference in time = 13.71 - 8.72 = 5 The correct answer is A.”
September 5, 2012
Anurag@Gurome posted a reply to DS: Remainder problem in the Data Sufficiency forum
“we can have all the values of remainder of m or n when divided by 3, satisfying m > n. so, it wont help. substituting simple values would be easy to rule out.”
September 5, 2012
Anurag@Gurome posted a reply to Source - GMAT Math Bible - Nova - Equations in the Problem Solving forum
“(x – 2y)(x + 2y) = 5 and (2x – y)(2x + y) = 35, then (x² - y²) / (x² + y²) (x – 2y)(x + 2y) = 5 implies x² - 4y² = 5 ... Equation (1) (2x – y)(2x + y) = 35 implies 4x² - y² = 35 ... Equation (2) Adding equations (1) and (2), 5x² - 5y = 40 or x² - y² = 8 Subtracting equation ...”
September 5, 2012
Anurag@Gurome posted a reply to Question number 87 OG12 in the Data Sufficiency forum
“See my post here: http://www.beatthegmat.com/og-12-ds-87-t115800.html”
September 4, 2012
Anurag@Gurome posted a reply to OG12 PS148 in the Problem Solving forum
“We have 10x/(x+y) + 10y/(x+y) + 10y/(x+y) = k. 10 + 10y/(x+y) = k. Now it is given that x < y. x + y < 2y. y/(x + y) > 1/2. 10y/(x + y) > 5. 10 + 10y/(x + y) > 15. Also since both x and y are positive, y/(x+y) < 1. 10 + 10y/(x + y) < 20. Therefore 15 < k ...”
September 4, 2012
Anurag@Gurome posted a reply to Francine's trip in the Problem Solving forum
“Let us take the total distance = 1 mile Then x% of 1 = x/100 So, Francine traveled x/100 mile at 40 mph. So, time taken = distance/speed = (x/100)/40 = x/4000 Remaining distance = 1 - x/100 = (100 - x)/100 Time taken to travel (100 - x)/100 mile at 60 mph = distance/speed = 12000/(x + 200) ...”
September 4, 2012
Anurag@Gurome posted a reply to Mixtures in the Problem Solving forum
“Algebraic Approach: Say, x part of 50% solution was replaced with x part of 30% solution. So, (1 - x)*50 + x*30 = 40 --> 50 - 50x + 30x = 40 --> 20x = 10 --> x = 1/2 The correct answer is D.”
September 4, 2012
Anurag@Gurome posted a reply to Mixtures in the Problem Solving forum
“Intuitive Approach: Just observe that the concentration of the final solution (40%) is exactly at the middle of the concentrations of the solutions mixed together (50% and 30%). Hence, exactly same amount of both solutions were mixed together, i.e. 1/2 of the original solution was replaced. ...”
September 4, 2012
Anurag@Gurome posted a reply to Mixtures in the Problem Solving forum
“Delete”
September 4, 2012
Anurag@Gurome posted a reply to Mixtures in the Problem Solving forum
“Delete”
September 4, 2012
Anurag@Gurome posted a reply to Need help to solve the question. in the Problem Solving forum
“Number of people who answered "yes" to Q1 = N/4 Of the people who answered "yes" to Q1, number of people who answered "yes" to Q2 = (1/3)(N/4) = N/12 So, number of people who answered "yes" to Q1 and Q2, both = N/12 Therefore, number of people who did ...”
September 4, 2012
“Say, number of workers in the day crew = w => Number of workers in the night crew = 4w/5. Say, total number of boxes loaded by the day crew = x => Number of boxes loaded by each of the workers in the day crew = x/w. => Number of boxes loaded by each of the workers in the night ...”
September 4, 2012
Anurag@Gurome posted a reply to Stereo in the Problem Solving forum
“Say the retail price is R% Hence, price of the stereo = Retail price + 6% tax on the retail price = R + 6% of R = R + 0.06R = 1.06R Now, 1.06R = 530 ---> R = 500 Price of the stereo in the neighboring state = 1.05R = $525 Hence, she could have saved$(530 - 525) = \$5 The ...”
September 4, 2012
Anurag@Gurome posted a reply to animals in the Problem Solving forum
“Probability of survival for each of the first 3 months of life = 1 - 1/10 = 9/10 So, from a group of 200 newborn members of the population, number expected to survive the first 3 months of life = 200 * 9/10 * 9/10 * 9/10 = 146 approx. The correct answer is B.”
September 4, 2012
Anurag@Gurome posted a reply to Are X n Y both positive in the Data Sufficiency forum
“(1) 2x - 2y = 1 x and y both positive means that point (x, y) is in the first quadrant. 2x - 2y = 1 implies y = x - 1/2, and it''s an equation of a line and the question asks whether this line is only in first quadrant, which is not possible; NOT sufficient. (2) x/y > 1 x and y have the ...”
September 3, 2012
Anurag@Gurome posted a reply to DS: Remainder problem in the Data Sufficiency forum
“The remainder of n/3 is 2 -> n = (3 * k1) + 2, where k1 =0,1,2.... when 10^z is divided by 3, remainder is 1. 10^z = 9 * k2 + 1, where k2 =0,1,2... so, 10^m + n = (9 * k2 + 1) + 3*k1 + 2 = (9 * k2) + (3 * k1) + 3. which is divisible by 3. hence, remainder is 0. for a number is divided by 3. ...”
September 3, 2012
Anurag@Gurome posted a reply to Sequence in the Data Sufficiency forum
“An = An-2 + 11, n > 2 A3 = A1 + 11, A5 = A3 + 11.... (so the odd numbers are in AP with initial term as A1 and common difference as 11) A4 = A2 + 11, A6 = A4 + 11 ... (so the even numbers are also in AP with initial term as A2 and common difference as 11) But the whole series taken is not in ...”
August 30, 2012
Anurag@Gurome posted a reply to best method? in the Problem Solving forum
“You can see my post here: http://www.beatthegmat.com/permutation-t114454.html”
August 30, 2012
Anurag@Gurome posted a reply to PRODUCT in the Problem Solving forum
“Let us assume that the two integers are x and y. x + y = 24 ... Equation 1 x² - y² = 48 ... Equation 2 Substitute the value of y from equation 1 in equation 2, we get, x² - (24 - x)² = 48 x² - (576 + x² - 48x) = 48 48x = 576 + 48 48x = 624 x = 13 y = 24 - 13 = 11 Therefore, x * y ...”
August 30, 2012
Anurag@Gurome posted a reply to K a positive in the Data Sufficiency forum
“In the question it is not mentioned whether k is integer. So, we should not assume it to be an integer. consider 1st option: if k > 1, K^3 will be greater than k, so |k^3| + 1 > k. if 0 < k < 1, k will be less than 1, so it will be less than |k^3| + 1. if k = 1 or 0, |K^3| + 1 ...”
August 29, 2012
Anurag@Gurome posted a reply to Gurome vs MBA Crystal Ball in the Lounge forum
“We suggest you take a free consultation from both Gurome and Crystal Ball and then evaluate the merits of each organization to reach a fair decision.”
August 29, 2012
Anurag@Gurome posted a reply to Multiple of? in the Data Sufficiency forum
“We can do this by Picking numbers approach. (1) b is a multiple of 3. If c = 1, b = 6, here b is not a multiple of 24. If c = 2, b = 24, here b is a multiple of 24. No definite answer; NOT sufficient. (2) c is odd. If c = 1, b = 6, here b is not a multiple of 24. If c = 7, b = 504, here b ...”
August 29, 2012
Anurag@Gurome posted a reply to y<2? in the Data Sufficiency forum
“given x, y > 0 considering option 1: take x = 3, y = 1 (these values satisfy x > 2y and y < 2) take x = 10, y = 4 (these values satisfy x > 2y, but does not satisfy y < 2) so, we can eliminate option A considering option 2: take x = 2, y = 1 (these values satisfy x < y + ...”
August 29, 2012
Anurag@Gurome posted a reply to Age in the Data Sufficiency forum
“take present age as x. considering option 1: age of carol 6 years ago = x-6 half her present age = x/2 so, x/2 = x-6 -> x = 12 can be answered with A alone considering option 2: age of carol 3 years from now = x + 3 age of carol 7 years ago = x -7 from the statement, x+3 = 3*(x-7) ...”
August 29, 2012
Anurag@Gurome posted a reply to Official Guide 13th Edition - Question #15 in the Data Sufficiency forum
“You can see my reply here: http://www.beatthegmat.com/og13-ds-q15-what-is-cube-root-of-w-t114709.html”
August 29, 2012
Anurag@Gurome posted a reply to GMAT Club DS in the Data Sufficiency forum
“consider option 1 (The sum of these integers is positive but smaller than 20) when we take 2,4,6,8 (4 consecutive positive integers) the sum is 20. but we need sum to be less than 20 and positive. so the numbers we are left are (0,2,4,6) , (-2,0,2,4). if we take (-4,-2,0,2) the sum is not ...”
August 29, 2012
Anurag@Gurome posted a reply to lima beans and brussel sprouts in the Data Sufficiency forum
“Say, number of students who eats in the cafeteria = n Hence, 2n/3 students dislikes Lima beans. Hence, (1 - 3/5)*(2n/3) = (2/5)*(2n/3) = 4n/15 students dislikes Lima beans but likes Brussels sprouts. Statement 1: n = 120 --> Sufficient Statement 2: (1 - 2/3)*n = 40 --> n = 3*40 = ...”
August 28, 2012
Anurag@Gurome posted a reply to Probability / Gmatprep CAT in the Data Sufficiency forum
“The required probability = Probability that the selected ball is white + Probability that the selected ball that have an even number painted on it = P(white) + P(even) - P(white & even) We are subtracting P(white & even) as the balls that are white as well as have an even number painted ...”
August 28, 2012
Anurag@Gurome posted a reply to Coordinate Geometry - 1 in the Data Sufficiency forum
“Hi ankur, when y2/x2 = 1/3, it does not mean y2 = 1 and x2 = 3. it can be any set of values that satisfy the ratio 1/3. for example when y2 = 2, x2 = 6 when y2 = 0.5, x2 = 1.5 we will have infinite set of values satisfying this condition”
August 28, 2012
Anurag@Gurome posted a reply to Company sales in the Data Sufficiency forum
“sales of company A in 2005 = SA5 sales of company A in 2006 = SA6 sales of company B in 2005 = SB5 sales of company B in 2006 = SB6 percent of sales of company A increase = (SA6 - SA5) * 100 / SA5 From 1, we can know SA5 = 0.25 * SB5 as we dont know value of SA6 and SB5. we cant answer ...”
August 27, 2012
Anurag@Gurome posted a reply to is v > 0 ? in the Data Sufficiency forum
“from vw = 16, we can understand that v and w are of same sign. (i.e both can be positive or negative). so we cant answer using this alone. from v + w = -10. we can understand that one of them or both should be negative for the sum to be -ve. so we cant answer using this alone. when we ...”
August 27, 2012
Anurag@Gurome posted a reply to Rephrasing. in the Data Sufficiency forum
“considering option a alone when b > a + 21 b - a > 21. so b - a can be 22, 23, 24, 25 .......... square root of 22 is not an integer, where as square root of 25 is an integer. so, we can`t answer with option a alone. considering option b alone b = a(a+1) = a^2 + a b - a = a^2 square ...”
August 27, 2012
Anurag@Gurome posted a reply to is a less than 50? in the Data Sufficiency forum
“if a is less than 80% of b. a should be less than 0.8b. that means a can be almost 0.8b or can be 06.b or 0.4b or 0 (any value less than 0.8b) considering option 1 alone.. lets take a = 0.8b so b -a = 20 -> b - 0.8b = 0.2b = 20 b = 100 so, a = 0.8 * 100 = 80 a > 50 in this case. a ...”
August 27, 2012
Anurag@Gurome posted a reply to Coordinate Geometry - 1 in the Data Sufficiency forum
“assume the co-ordinates of S are (x,y). considering each option alone: 1) given: slope of OS = 1/3 and co-ordinates of O and T are (0,0)and(5,0) respectively. OS slope is 1/3 slope of line when given two points(m) = (y1 - y2)/(x1 - x2) so, we will get the line equation of OS. the point can be ...”
August 24, 2012
Anurag@Gurome posted a reply to x > |y|? in the Data Sufficiency forum
“given: x + y > 0. let us take the 1st option x > y. 1. if x > 0, y >= 0 then x + y > 0. As x > y so will be x > |y|. if x > 0, y < 0. for x + y > 0. positive value should be more than negative value. x + y > 0 can be written as X - |y| > 0 -> x > ...”
August 24, 2012
Anurag@Gurome posted a reply to exponents in the Problem Solving forum
“1/2^10 + 1/2^11 + 1/2^12 + 1/2^12 = 1/2^10(1 + 1/2 + 1/2² + 1/2²) = 1/2^10(1 + 1/2 + 1/4 + 1/4) = 1/2^10(1 + 1/2 + 1/2) = 1/2^10(1 + 1) = 2/2^10 = 1/2^9 The correct answer is C.”
August 24, 2012