question: A man rows his boat 90 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 5 kmph
(B) 7 kmph
(C) 9 kmph
(D) 8 kmph
(E) 1 kmph
answer: Stream of consciousness: Speed downstream = d/t = 90/(2 1/2) = 36 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (36 - 18)/2 = 9 kmph The answer is (C).
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question: A train running at the speed of 60 km/hr crosses a pole in 3 seconds. Find the length of the train.
Options:
(A) 150 m
(B) 50 m
(C) 75 m
(D) 135 m
(E) 60 m
answer: Stream of consciousness: Speed = 60*(5/18) m/sec = 50/3 m/sec
Length of Train (Distance) = Speed * Time
(50/3) * 3 = 50 meter The answer is (B).
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question: John makes $40 a week from his job. He earns a raise and now makes $60 a week. What is the % increase?
Options:
(A) 16%
(B) 16.66%
(C) 18%
(D) 21%
(E) 50%
answer: Stream of consciousness: Increase = (20/40)*100 = 50%. The answer is (E).
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question: One copy machine can make 30 copies a minute, and a second copy machine makes 20 copies a minute. If the two copiers work together, how long would it take them to make 2,000 copies?
Options:
(A) 20 minutes
(B) 40 minutes
(C) 45 minutes
(D) 50 minutes
(E) 55 minutes
answer:
Stream of consciousness: Total work done by both machines in a minute = 30 + 20 = 50 copies
Total number of copies required = 2000
Time = 2000/50 = 40 mins The answer is (B).
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