Question: Alice, Benjamin, and Carol each try independently to win a carnival game. If their individual probabilities for success are 2/5, 3/8, and 2/7, respectively, what is the probability that exactly two of the three players will win but one will lose?
Options:
(A) 3/140
(B) 1/280
(C) 3/280
(D) 4/56
(E) 77/280
Answer: P = P(A wins, B wins, C loses) + P(A wins, B loses, C wins) + P(A loses, B wins, C wins) = 2/5*3/8*5/7 + 2/5*5/8*2/7 + 3/5*3/8*2/7 = 77/280.
The answer is (E).

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) 7 days
(B) 8 days
(C) 3 days
(D) 9 days
(E) 2 days
Answer: 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 is (B).

Question: A telephone company needs to create a set of 3-digit area codes. The company is entitled to use only digits 2, 4 and 6, which can be repeated. If the product of the digits in the area code must be even, how many different codes can be created?
Options:
(A) 27
(B) 22
(C) 24
(D) 26
(E) 30
Answer: Total # of codes possible is 3*3*3 = 27. Oit of those 27 codes
The answer is (A).

Question: A wheel rotates 10 times every minute and moves 20 cm during each rotation. How many metres does the wheel move in one hour?
Options:
(A) 6 metre
(B) 12 metre
(C) 120 metre
(D) 1200 metre
(E) 130 metre
Answer:
Number of times wheel moves in 1 hour = 10 * 60 = 600
:. Distance moves = (600 *20) cms = 12000 cms
In metres = 120 metre
The answer is (C).