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 50 m long takes 6 sec to cross a man walking at 5 kmph in a direction opposite to that of the train . find the speed of the train ? 
Options: a ) 15 kmph , b ) 25 kmph , c ) 35 kmph , d ) 45 kmph , e ) 55 kmph
b

Problem: if 3 men or 4 women can do a piece of work in 16 days , in how many days can 12 men and 8 women do the same piece of work ? 
Options: a ) 8 / 3 , b ) 6 , c ) 5 , d ) 4 , e ) 3
a

Problem: a man can do a piece of work in 4 days , but with the help of his son he can do it in 3 days . in what time can the son do it alone ? 
Options: a ) 12 days , b ) 6 days , c ) 5 days , d ) 4 days , e ) none of these

a