question: A and B complete a work in 8 days. A alone can do it in 14 days. If both together can do the work in how many days?
Options:
(A) 5 days
(B) 8 days
(C) 6 days
(D) 3.15 days
(E) 2.75 days
answer: Stream of consciousness: 1/8 + 1/14 = 11/56
56/11 = 5 days The answer is (A).
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question: Ravi can do a piece of work in 15 days while Prakash can do it in 30 days. In how many days will they finish it together?
Options:
(A) 11 days
(B) 9 days
(C) 8 days
(D) 12 days
(E) 10 days
answer: Stream of consciousness: 1/15 + 1/30 = 3/30
10/1 = 10 days The answer is (E).
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question: The average of seven numbers is 18. The average of first three numbers is 14 and the average of last three numbers is 19. What is the middle number?
Options:
(A) 25
(B) 27
(C) 29
(D) 32
(E) 34
answer: Stream of consciousness: The total of seven numbers = 7X18 = 126
The total of first 3 and last 3 numbers is = 3 X 14+3 X 19 = 99
So, the middle number is (126 - 99 ) = 27 The answer is (B).
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question: The average of first six prime numbers greater than 65 is?
Options:
(A) 55
(B) 77
(C) 56
(D) 67
(E) 98
answer:
Stream of consciousness: 67 + 71 + 73 + 79 + 83 + 89 = 462/6 = 77 The answer is (B).
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