q: In what time will a railway train 60 m long moving at the rate of 36 kmph pass a telegraph post on its way?
Options:
(A) 5 sec
(B) 4 sec
(C) 3 sec
(D) 6 sec
(E) 1 sec
a: Stream of consciousness: T = 60/36 * 18/5 = 6 sec The answer is (D).
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q: The inverse ratio of 6: 2: 1 is?
Options:
(A) 2:3:7
(B) 2:3:9
(C) 2:3:2
(D) 1:3:6
(E) 2:3:1
a: Stream of consciousness: 1/6: 1/2: 1/1 = 1:3:6 The answer is (D).
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q: Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 5 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
Options:
(A) 60 gallons
(B) 200 gallons
(C) 120 gallons
(D) 180 gallons
(E) 130 gallons
a:
Stream of consciousness: Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 5 gallonsVolume of whole = 5 * 40 = 200 gallons. The answer is (B).
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