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'.

Problem: a train 100 m long can cross an electric pole in 20 sec and then find the speed of the train ? 
Options: a ) 19 kmph , b ) 18 kmph , c ) 72 kmph , d ) 17 kmph , e ) 91 kmph
b

Problem: a train passes a station platform in 60 sec and a man standing on the platform in 20 sec . if the speed of the train is 54 km / hr . what is the length of the platform ? 
Options: a ) 615 m , b ) 420 m , c ) 168 m , d ) 197 m , e ) 691 m
b

Problem: a person walks from one end to the other of a 100 - meter long moving walkway at a constant rate in 50 seconds , assisted by the walkway . when this person reaches the end , they reverse direction and continue walking with the same speed , but this time it takes 150 seconds because the person is traveling against the direction of the moving walkway . if the walkway were to stop moving , how many seconds would it take this person to walk from one end of the walkway to the other ? 
Options: a ) 63 , b ) 66 , c ) 69 , d ) 72 , e ) 75

e