Reasoning: According to the information in the question the maximum range would be between 510 and 780(270). The minimum range would be the greatest range for any one individual, which is listed in the problem as 130. So the difference between these would be 270-130 or 140.
Ans: (D)
Question: Three people took GMAT practice tests in which the minimum and maximum possible scores are 200 and 800, respectively. They each took a test 3 times, and no one scored below 510 or over 780. If the individual ranges of the three people's scores in those 3 practice tests were 20, 90 and 130, what is the difference between the maximum and minimum possible ranges of all their scores put together.
Options:
(A) 70
(B) 80
(C) 90
(D) 140
(E) 170
Rationale: A + B = 1/20 + 1/15 = 7/60
A + C = 1/20 + 1/12 = 8/60
7/60 + 8/60 = 15/60 = 1/4
4 days * 2 = 8 days
The answer: (B)
Question: A can do a piece of work in 20 days. B in 15 days A and C in 12 days. In how many days can A finish the work if he is assisted by B on one day and C on the next, alternately?
Options:
(A) 9 days
(B) 8 days
(C) 5 days
(D) 54 days
(E) 2 days
Reasoning: 6a2 = 6 * 3a * 3a = 54a2
Ans: (B)
Question: The edge of a cube is 3a cm. Find its surface?
Options:
(A) 64a2 cm2
(B) 54a2 cm2
(C) 84a2 cm2
(D) 24a2 cm2
(E) 34a2 cm2
Rationale: 6C2 * 5C2 * 3C1 = 15*10*3 = 450.
The answer: (D)
Question: An analyst will recommend a combination of 2 industrial stocks, 2 transportation stocks, and 1 utility stocks. If the analyst can choose from 6 industrial stocks, 5 transportation stocks, and 3 utility stocks, how many different combinations of 5 stocks are possible?
Options:
(A) 12
(B) 460
(C) 60
(D) 450
(E) 720
Reasoning: He has has ten patterns of chairs and eight patterns of tables
Hence, A chair can be arranged in 10 ways and
A table can be arranged in 6 ways
Hence one chair and one table can be arranged in 10 x 6 ways = 60 ways
Ans: (B)
Question: An design manager has 10patterns of chairs & 6patterns of tables. In how many ways can he make a pair of table & chair?
Options:
(A) 20
(B) 60
(C) 80
(D) 90
(E) 100
Reasoning: P = (P*3*R)/100
R = 33 1/3%
Ans: (B)
Question: In what time a sum of money double itself at 3% per annum simple interest?
Options:
(A) 33 1/7%
(B) 33 1/3%
(C) 33 1/2%
(D) 33 7/3%
(E) 33 5/3%