q: Three 6 faced dice are thrown together. The probability that exactly two dice show the same number on them is?
Options:
(A) 5/15
(B) 5/12
(C) 5/19
(D) 5/12
(E) 5/11
a: Using question number 11 and 12, we get the probability as
1 - (1/36 + 5/9) = 5/12 The answer is (B).
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q: If the ratio of boys to girls in a class is B and the ratio of girls to boys is G; then 10(B + G) is ?
Options:
(A) Equal to 3
(B) Less than 3
(C) More than 10
(D) Less than 10
(E) none of these
a: Let number of boys = x
Let number of girls = y
Therefore x/y = B and y/x = G
10(B + G) = 10[(x/y) + (y/x)] = 10[(x2 + y2)/xy] > 10 The answer is (C).
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q: 10 men and 15 women together can complete a work in 6 days. It takes 100 days for one man alone to complete the same work. How many days will be required for one woman alone to complete the same work?
Options:
(A) 127 days
(B) 667 days
(C) 177 days
(D) 187 days
(E) 225 days
a: 1 man's 1 day work = 1/100
(10 men + 15 women)'s 1 day work = 1/6
15 women's 1 day work = (1/6 - 10/100) = 1/15
1 woman's 1 day work = 1/225
1 woman alone can complete the work in 225 days. The answer is (E).
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q: In what time will a railway train 40 m long moving at the rate of 36 kmph pass a telegraph post on its way?
Options:
(A) 3
(B) 5
(C) 9
(D) 4
(E) 7
a:
T = 40/36 * 18/5 = 4 sec The answer is (D).
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