q: Pipes A and B can fill a cistern in 8 and 24 minutes respectively. They are opened an alternate minutes. Find how many minutes, the cistern shall be full?
Options:
(A) 11
(B) 12
(C) 99
(D) 75
(E) 72
a: 1/8 + 1/24 = 1/6
6 * 2 = 12 The answer is (B).
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q: A person spends 40% of his salary on food, 25% on house rent, 15% on entertainment and 5% on conveyance. If his savings at the end of the month is Rs. 1200, then his salary per month in rupees is:
Options:
(A) 4000
(B) 6000
(C) 8000
(D) 10000
(E) None of these
a: Total expenditure = 40 + 25 + 15 + 5 = 85%
Saving = (100 - 85) = 15%
15/100 Salary = 1200, Salary = 8000 Rs. The answer is (C).
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q: Two trains are moving at 50 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 7 1/6 sec
(B) 7 3/2 sec
(C) 7 1/7 sec
(D) 7 1/2 sec
(E) 3 3/2 sec
a: 70 + 50 = 120 * 5/18 = 100/3 mps
D = 150 + 100 = 250 m
T = 250 * 3/100 = 15/2 = 7 1/2 sec The answer is (D).
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q: How much 60% of 50 is greater than 40% of 30?
Options:
(A) 18
(B) 28
(C) 29
(D) 11
(E) 12
a:
(60/100) * 50 (40/100) * 30
30 - 12 = 18 The answer is (A).
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