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 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: john and lewis leave city a for city b simultaneously at 6 a . m in the morning driving in two cars at speeds of 40 mph and 60 mph respectively . as soon as lewis reaches city b , he returns back to city a along the same route and meets john on the way back . if the distance between the two cities is 240 miles , how far from city a did john and lewis meet ? 
Options: a ) 150 miles , b ) 160 miles , c ) 140 miles , d ) 170 miles , e ) 200 miles
b

Problem: a man walking at 3 / 4 th of the speed , reaches his office late by 2 hours . what is the usual time ? 
Options: a ) 5 hours , b ) 3 hours , c ) 6 hours , d ) 12 hours , e ) 15 hours

c