q: A train 250 m long is running at a speed of 27 km/hr. In what time will it pass a bridge 200 m long?
Options:
(A) 40
(B) 45
(C) 50
(D) 55
(E) 60
a: Stream of consciousness: Speed = 27 * 5/18 = 15/2 m/sec
Total distance covered = 250 + 200 = 450 m
Required time = 450 * 2/15 = 60 sec The answer is (E).
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q: Two trains are moving at 85 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) 5 25/31 sec
(B) 7 1/17 sec
(C) 7 2/2 sec
(D) 8 1/2 sec
(E) 7 1/9 sec
a: Stream of consciousness: 70 + 85 = 155 * 5/18 = 775/18 mps
D = 150 + 100 = 250 m
T = 250 * 18/775 = 180/31 = 5 25/31 sec The answer is (A).
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q: The average of 11 results is 55, if the average of first five results is 49 and that of the last seven is 52. Find the fifth result?
Options:
(A) 4
(B) 5
(C) 7
(D) 8
(E) 9
a:
Stream of consciousness: 1 to 11 = 11 * 55 = 605
1 to 5 = 5 * 49 = 245
5 to 11 = 7 * 52 = 364
5th = 245 + 364 605 = 4 The answer is (A).
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