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'.

[Q]: Problem: a train speeds past a pole in 15 sec and a platform 100 m long in 25 sec , its length is ? 
Options: a ) 158 m , b ) 150 m , c ) 110 m , d ) 130 m , e ) 157 m
[A]: b


[Q]: Problem: a train is 485 meter long is running at a speed of 45 km / hour . in what time will it pass a bridge of 140 meter length 
Options: a ) 20 seconds , b ) 30 seconds , c ) 40 seconds , d ) 50 seconds , e ) none of these
[A]: d


[Q]: Problem: two pipes can fill the cistern in 10 hr and 12 hr respectively , while the third empty it in 30 hr . if all pipes are opened simultaneously , then the cistern will be filled in 
Options: a ) 6.67 hr , b ) 8 hr , c ) 8.5 hr , d ) 10 hr , e ) none of these
[A]:
a