Search found 94 matches
If (x^3 - 2x^2 + x - 1)^2 - 1=(x - a) (x - b) (x - c) (x - d) (x - e) (x - f), then abcdef=? A. 0 B. 25 C. -25 D. 24 E. -24 OA is A How to approach this question ? Thanks Use difference of two squares to find the roots: a^2 - b^2 = (a+b)(a-b) (x^3 - 2x^2 + x - 1)^2 - 1 a = x^3 - 2x^2 + x - 1 b = 1 ...
- by mbawisdom
Tue Mar 06, 2018 8:01 am- Forum: Problem Solving
- Topic: If (x^3 - 2x^2 + x - 1)^2 - 1=(x - a) (x - b) (x - c) (x - d
- Replies: 9
- Views: 1378
What is the average (arithmetic mean) of w, x, y, z, and 10? (1) The average (arithmetic mean) of w and y is 7.5; the average (arithmetic mean) of x and z is 2.5 (2) -(-z - y -x - w) = 20 The OA is the option D . How can I use statement (1) to get an answer here? Experts, may you help me? I'd be th...
- by mbawisdom
Tue Mar 06, 2018 6:07 am- Forum: Data Sufficiency
- Topic: What is the average (arithmetic mean) of w, x, y, z, and 10?
- Replies: 2
- Views: 2345
A company has 400 employees, 20 percent of whom have 5 or more years of work experience. If 40 additional employees are to be hired and all of the present employees remain, how many of the additional employees must have 5 or more years of work experience in order to raise the percentage of employee...
- by mbawisdom
Tue Mar 06, 2018 6:01 am- Forum: Problem Solving
- Topic: A company has 400 employees, 20 percent of whom have 5...
- Replies: 2
- Views: 701
Cameron can paint a room in c hours. Cameron and Mackenzie, working together, can paint the room in d hours. In terms of c and d, how long in hours would it take Mackenzie, working alone, to paint the room? $$A.\ 2d-c$$ $$B.\ \frac{c+d}{cd}$$ $$C.\ \frac{c-d}{cd}$$ $$D.\ \frac{cd}{c+d}$$ $$E.\ \fra...
- by mbawisdom
Tue Mar 06, 2018 5:54 am- Forum: Problem Solving
- Topic: Cameron can paint a room in c hours. Cameron and Mackenzie..
- Replies: 3
- Views: 798
Sequence A is defined by the equation An = 3n + 7, where n is an integer greater than or equal to 1. If set B is comprised of the first x terms of sequence A, what is the median of set B ? (1) The sum of the terms in set B is 275. (2) The range of the terms in set B is 30 Which of the statements is...
- by mbawisdom
Tue Mar 06, 2018 5:37 am- Forum: Data Sufficiency
- Topic: Sequence A is defined by the equation An = 3n + 7
- Replies: 4
- Views: 3154
What is the average (arithmetic mean) of x and y? (1) The average of x + 3 and y + 5 is 14. (2) The average of x, y, and 16 is 12. The OA is the option D . I know that the statement (2) is sufficient. But, how can I prove that the statement (1) is sufficient? Avg = (x + y)/2 --> we need to be able ...
- by mbawisdom
Tue Mar 06, 2018 4:21 am- Forum: Data Sufficiency
- Topic: What is the average (arithmetic mean) of x and y?
- Replies: 2
- Views: 1117
In a certain game only one player can win and only one player always eventually wins. James, Austin, and Katelyn play this game together 3 times in a row. What is the probability that Katelyn wins at least one of the 3 games.? (1) The probability that either James or Austin wins the game is 3/4 (2)...
- by mbawisdom
Tue Mar 06, 2018 4:09 am- Forum: Data Sufficiency
- Topic: In a certain game only one player can win and only one playe
- Replies: 1
- Views: 682
If ab=0, is |a-b|>0? 1) a=0 2) b<0 The OA is the option B . Experts can you tell me why is not sufficient the statement (1)? I don't understand. I think the correct option is D. If ab = 0, then we have three states of the world: 1. a = 0, b doesn't equal 0 2. a doesn't equal zero, b = 0 3. a = 0, b...
- by mbawisdom
Tue Mar 06, 2018 1:06 am- Forum: Data Sufficiency
- Topic: If ab=0, is |a-b|>0?
- Replies: 2
- Views: 727
If Ruth began a job and worked continuously until she finished, at what time of day did she finish the job? (1) She started the job at 8:15 a.m. and at noon of the same day she had worked exactly half of the time that it took her to do the whole job. (2) She was finished exactly 7.5 hours after she...
- by mbawisdom
Mon Mar 05, 2018 5:55 pm- Forum: Data Sufficiency
- Topic: If Ruth began a job and worked continuously until she finish
- Replies: 1
- Views: 599
All 250 files on Sam's hard drive are infected by either a virus or a worm or both. The number of files that are infected only by a worm is 2.5 times the number of files that are infected by both a virus and a worm. If 50% of the files were not infected by a virus, how many of Sam's files were NOT ...
- by mbawisdom
Mon Mar 05, 2018 5:37 pm- Forum: Problem Solving
- Topic: All 250 files on Sam's hard drive are infected
- Replies: 2
- Views: 965
In a group of 250 adults, is the number of married (not necessarily to other group members) people at least 75? (1) At least 65 percent of the men in the group are married. (2) At least 30 percent of the women in the group are married. Is there a sufficient statement in this problem? OA C (1) is no...
- by mbawisdom
Mon Mar 05, 2018 4:49 pm- Forum: Data Sufficiency
- Topic: In a group of 250 adults, is the number
- Replies: 2
- Views: 746
Working alone at a constant rate, Alan can paint a house in an hour. Working alone at a constant rate, Bob can point 1/4 of the same house in b hours. Working together, Alan and Bob can paint 1/3 of the house in c hours. What is the value of b in terms of a and c? A. (3ac)/(a+c) B. (4a-12c)/(3ac) C...
- by mbawisdom
Mon Mar 05, 2018 4:27 pm- Forum: Problem Solving
- Topic: Working alone at a constant rate, Alan can paint a house...
- Replies: 3
- Views: 938
A magician has five animals in his magic hat: 3 doves and 2 rabbits. If he pulls two animals out of the hat at random, what is the chance that he will have a matched pair? A. 2/5 B. 3/5 C. 1/5 D. 1/2 E. 7/5 I'm confused how to set up the formulas here. Can any experts help? OA A For a pair he will ...
- by mbawisdom
Mon Mar 05, 2018 2:03 pm- Forum: Problem Solving
- Topic: A magician has five animals in his magic hat
- Replies: 6
- Views: 1115
Machine M can produce x units in 3/4 of the time it takes machine N to produce x units. Machine N can produce x units in 2/3 the time it takes machine O to produce x units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N? A. 1/2 B. 1/3 C....
- by mbawisdom
Mon Mar 05, 2018 1:51 pm- Forum: Problem Solving
- Topic: Machine M can produce x units in 3/4 of the time it takes...
- Replies: 4
- Views: 910
A cyclist riding in fog overtakes a man walking at the speed of 3 km/h. If the man could see the cyclist for 4 minutes an up to a distance of 100m, what is the speed of the cyclist in km/h? A. 1.5 B. 2.5 C. 4.5 D. 5 E. 6 The OA is C . I try to solve it as follow, $$Dist=100m\ =\frac{1}{10}km.$$ $$T...
- by mbawisdom
Mon Mar 05, 2018 1:44 pm- Forum: Problem Solving
- Topic: A cyclist riding in fog overtakes a man walking...
- Replies: 3
- Views: 709