In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: a train is 360 meter long is running at a speed of 30 km / hour . in what time will it pass a bridge of 140 meter length ? 
Options: a ) 87 , b ) 69 , c ) 60 , d ) 72 , e ) 21
[EX A]: c

[EX Q]: Problem: to fill a tank , 25 buckets of water is required . how many buckets of water will be required to fill the same tank if the capacity of the bucket is reduced to 3 / 10 of its present ? 
Options: a ) 61.5 , b ) 60.5 , c ) 63.5 , d ) 83.333 , e ) 64.5
[EX A]: d

[EX Q]: Problem: one gear of pulley rotates at a speed of 3 rev / sec another gear roates at 5 rev / sec . if both start together after how many seconds will they be together again 
Options: a ) 3 sec , b ) 5 sec , c ) 15 sec , d ) 20 sec , e ) 25 sec
[EX A]:
c