Search found 1085 matches
- by pemdas
Sun Feb 03, 2013 6:36 pm- Forum: Problem Solving
- Topic: Minimum
- Replies: 12
- Views: 1633
Please don't shower bats at me for solving this question, this way ! If x,y>0, xy=6 then what is the minimum of 3x+5y ? 1)6sqrt(10) 2)sqrt(30) 3)2sqrt(10) 4)3aqrt(6) xy = 6, Implies y =6/x The expression 3x + 5y = 3x + (30/x) = (3x^2 + 30)/x Maximum/Minimum value of a function f(x) can be found by ...
- by pemdas
Sun Feb 03, 2013 5:08 pm- Forum: Problem Solving
- Topic: Minimum
- Replies: 12
- Views: 1633
IMO A I tend to use calculus to solve this type (a very basic concept of calculus though) Info - (x) = k(x - a)(x - b) Simplifying (x) = kx^2 -kx(a+b) +abx not quite right, simplifying we get P(x)= k*x^2-k(a+b)*x+kab d(x) = 2kx - k(b+a) equating to zero for maximum and dividing equation by k (const...
- by pemdas
Sun Feb 03, 2013 4:39 pm- Forum: Data Sufficiency
- Topic: The profit function when Company C
- Replies: 10
- Views: 2304
If an integer n is to be chosen at random from the integers 1 to 96, inclusive, what is the probability that n(n+1)(n+2) will be divisible by 8? A) 1/4 B) 3/8 C) 1/2 D) 5/8 E) 3/4 #GMAT Prep Question Bank set - Difficulty=Hard question. n(n+1)(n+2) must be divisible by 2^3 96 contains 48 twos (96/2...
- by pemdas
Sat Nov 10, 2012 11:10 am- Forum: Problem Solving
- Topic: Probability to chose numbers
- Replies: 4
- Views: 950
Enjoy... A sweetseller has 420 Dark chocolates and 130 Milk chocolates. She wants to stack them in such a way that each stack has the same number, and they take up the least area of the tray. What is the number of that can be placed in each stack for this purpose? 420= 2 *2*3* 5 *7 130= 2*5 *13 420...
- by pemdas
Mon Nov 05, 2012 2:19 pm- Forum: Problem Solving
- Topic: Sweet Problem
- Replies: 1
- Views: 810
did you understand the logic behind this question? why to ask about this gibberish by official explanation if we knew about s and r (integers or not integers) our task would be simplified to st(1) Suff. Since we know nothing about s and r, there could be always four integers (case when s and r are i...
- by pemdas
Sun Nov 04, 2012 5:36 pm- Forum: Data Sufficiency
- Topic: QR #49: How many integers n are there such that r<n<s
- Replies: 7
- Views: 7113
can someone please explain why the answer is E Is it b/c y is indeterminable when r = 5? is "indeterminable" an ambiguous answer? (y+3)(y-1) - (y-2)(y-1) = r(y-1), what is the value of y? (1) r^2 = 25 (2) r = 5 thanks Yes, factoring out (y-1) will give y+3-y+2=r and further r=5 only when ...
- by pemdas
Sun Nov 04, 2012 5:20 pm- Forum: Data Sufficiency
- Topic: equations / squares problem
- Replies: 2
- Views: 1027
Enjoy.. The price of pens has increased over the years. Each year for the last 7 years the price has increased, and the new price is the sum of the prices for the two previous years. Last year a pen cost 60 rupees. How much does a pen cost today? How much did a pen cost 7 years ago? let's denote ye...
- by pemdas
Sun Nov 04, 2012 3:14 pm- Forum: Problem Solving
- Topic: Inflation
- Replies: 2
- Views: 1086
Two tins A and B contain mixtures of wheat and rice. In A, the weights of wheat and rice are in the ratio 2 : 3 and in B they are in the ratio 3 : 7. What quantities must be taken from A and B to form a mixture containing 5 kg of wheat and 11 kg of rice? no need to mystify the weighted averages as ...
- by pemdas
Sun Nov 04, 2012 12:55 pm- Forum: Problem Solving
- Topic: ratios / fraction problem
- Replies: 20
- Views: 12914
x is the sum of y consecutive integers. w is the sum of z consecutive integers. If y = 2z, and y and z are both positive integers, then each of the following could be true EXCEPT A) x = w B) x > w C) x/y is an integer D) w/z is an integer E) x/z is an integer y=2z implies we have even number of the...
- by pemdas
Sun Nov 04, 2012 4:02 am- Forum: Problem Solving
- Topic: Crazy Consecutives
- Replies: 1
- Views: 1082
One millisecond is 0.001 of a second. The costs for a single run of a computer program are $1.07 for operating system overhead, $0.023 per millisecond of computer time, and $4.35 for the mounting of a data tape. What is the total of these three costs for 1 run of a program that requires 1.5 seconds...
- by pemdas
Sat Nov 03, 2012 11:03 am- Forum: Problem Solving
- Topic: Millisecond computer program
- Replies: 2
- Views: 1215
Do people have any idea in solving the following question ? S = x^3 + 3^x Is S > 0? (1) x < 0 (2) | x | > 1 Answer C [spoiler]I only face problem when i combine the two statements and don't know which way to go from there. Please explain with the help of examples.[/spoiler] Thanks & Regards Vin...
- by pemdas
Sat Nov 03, 2012 10:57 am- Forum: Data Sufficiency
- Topic: Tough question on absolute value & inequalities
- Replies: 6
- Views: 4809
A lemming tuns from a point A to a cliff 4m/s, jumps over the edge at B falls to C at an average speed of 25m/s. If the total distance from A to C is 500m and the time taken for the journey is 41 seconds, find the height of BC of the cliff. A->cliff->B->C 4x+25y=500 (x+y)=41, where x is time spent ...
- by pemdas
Sat Nov 03, 2012 10:08 am- Forum: Problem Solving
- Topic: Word Problem
- Replies: 1
- Views: 1877
I did't get this method, anybody please explainAbhiJ wrote:There is no need for graphical or need to find equation of RP.
- by pemdas
Fri Nov 02, 2012 6:40 pm- Forum: Problem Solving
- Topic: Beat this: Coordinate Geometry
- Replies: 14
- Views: 4177
factor out 2 --> 2(1+√6)/2 = 1+√6
granite wrote:(2+2√6)/2 =
A: √6
B: 2√6
C: 1 + √6
D: 1 + 2√6
E: 2 + √6
From the GMAT Quantitative Review 2nd edition.
- by pemdas
Fri Nov 02, 2012 12:28 pm- Forum: Problem Solving
- Topic: Operations of radical expressions
- Replies: 1
- Views: 1740