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: an electric pump can fill a tank in 6 hours . because of a leak in the tank , it took 12 hours to fill the tank . if the tank is full , how much time will the leak take to empty it ? 
Options: a ) 10 hours , b ) 12 hours , c ) 8 hours , d ) 5 hours , e ) 15 hours
[EX A]: b

[EX Q]: Problem: if 36 men can do a piece of work in 5 hours , in how many hours will 15 men do it ? 
Options: a ) 12 , b ) 38 , c ) 60 , d ) 88 , e ) 72
[EX A]: a

[EX Q]: Problem: a 470 m long train is running at a speed of 55 km / hr . it crossed a platform of length 520 m in ? 
Options: a ) 41.1 sec , b ) 64.8 sec , c ) 31.8 sec , d ) 50.4 sec , e ) none of the above
[EX A]:
b