q: A train of 24 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 1.3 km long?
Options:
(A) 2 mins 14 sec
(B) 2 mins 34 sec
(C) 168 sec
(D) 344 sec
(E) 2 mins 44 sec
a: D = 25 * 60 + 1300 = 2800 m
T = 2800/60 * 18/5 = 168 se The answer is (C).
--
q: Express 60 mps in kmph?
Options:
(A) 200
(B) 182
(C) 216
(D) 127
(E) 400
a: 60 * 18/5 = 216 kmph The answer is (C).
--
q: On average, the bottle-nosed dolphin comes up for air once every three minutes; the beluga whale, a close relative, comes up for air on average once every nine minutes. The number of times a bottle-nosed dolphin would come up for air in a 24 hour period is approximately what percent greater than the number of times a beluga whale would come up for air in that same period?
Options:
(A) 150%
(B) 200%
(C) 250%
(D) 300%
(E) 350%
a: Dolphin once in 3 min;
Beluga once in 9 min;
So, dolphin comes up 3 times frequently than beluga, which is 300% (9-3)/2*100. The answer is (D).
--
q: A bullet train 140 m long is running at 60 kmph. In how much time will it pass a platform 210 m long?
Options:
(A) 34 Seconds
(B) 22 Seconds
(C) 21 Seconds
(D) 24 Seconds
(E) 29 Seconds
a:
Distance travelled = 140 + 210m = 350m
Speed = 60 * 5/8 = 50/3m
Time = 350 * 3/50 = 21 Seconds The answer is (C).
--