q: The average age of 8 men increases by 2 years when two women are included in place of two men of ages 20 and 24 years. Find the average age of the women?
Options:
(A) 5
(B) 10
(C) 50
(D) 40
(E) 30
a: 20 + 24 + 8 * 2 = 60/2 = 30 The answer is (E).
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q: The average of seven numbers is 18. The average of first three numbers is 16 and the average of last three numbers is 20. What is the middle number?
Options:
(A) 20
(B) 22
(C) 25
(D) 18
(E) 24
a: The total of seven numbers = 7X18 = 126
The total of first 3 and last 3 numbers is = 3 X 16+3 X 20 = 108
So, the middle number is (126 - 108 ) = 18 The answer is (D).
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q: A Train requires 10 seconds to pass a pole while it requires 35 seconds to cross a stationary train which is 500 mtrs long. Find the speed of the train.
Options:
(A) 68 kmph
(B) 70 kmph
(C) 72 kmph
(D) 60 kmph
(E) 50 kmph
a: In 10s the train crosses the pole and in 35 sec the train crosses one more stationary train
In 25 sec the train travels a distance of 500 mtrs
Speed = 500/25 = 20 m/s = 20 (3600/1000) = 20 * 18/5 = 72 kmph The answer is (C).
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q: What is the greatest positive integer x such that 2^x is a factor of 8^10?
Options:
(A) 5
(B) 9
(C) 10
(D) 20
(E) 30
a:
8^10 = (2^3)^10 = 2^30 The answer is (E).
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