q: Alice, Benjamin, and Carol each try independently to win a carnival game. If their individual probabilities for success are 1/5, 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) 1/28
(C) 3/56
(D) 3/35
(E) 7/40
a: P = P(A wins, B wins, C loses) + P(A wins, B loses, C wins) + P(A loses, B wins, C wins) = 1/5*3/8*5/7 + 1/5*5/8*2/7 + 4/5*3/8*2/7 = 7/40. The answer is (E).
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q: 4000 was divided into two parts such a way that when first part was invested at 3% and the second at 5%, the whole annual interest from both the investments is Rs.144, how much was put at 3%?
Options:
(A) 2800
(B) 2500
(C) 2700
(D) 3000
(E) 3500
a: (x*3*1)/100 + [(4000 - x)*5*1]/100 = 144
3x/100 + 200 5x/100 = 144
2x/100 = 56 e x = 2800 The answer is (A).
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q: A wheel rotates 20 times every minute and moves 20 cm during each rotation. How many metres does the wheel move in one hour?
Options:
(A) 4 metre
(B) 12 metre
(C) 240 metre
(D) 2400 metre
(E) 130 metre
a: Number of times wheel moves in 1 hour = 20 * 60 = 1200
:. Distance moves = (1200*20) cms = 24000 cms
In metres = 240 metre The answer is (C).
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q: The average of nine numbers is 15. The average of first four numbers is 11 and the average of last four numbers is 14. What is the middle number?
Options:
(A) 19
(B) 20
(C) 35
(D) 31
(E) 27
a:
The total of nine numbers = 9X15 = 135
The total of first 4 and last 4 numbers is = 4 X 11+4 X 14 = 100
So, the middle number is (135 - 100 ) = 35 The answer is (C).
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