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'.
--------
Question: Problem: a train 140 meters long takes 6 seconds to cross a man walking at 5 kmph in the direction opposite to that of the train . find the speed of the train . 
Options: a ) 45 kmph , b ) 50 kmph , c ) 55 kmph , d ) 60 kmph , e ) 79 kmph

Answer: e


Question: Problem: a is twice as good a workman as b and together they complete a work in 12 days . in how many days a alone can do the work ? 
Options: a ) 32 , b ) 33 , c ) 34 , d ) 35 , e ) 36

Answer: e


Question: Problem: 30 men can do a work in 40 days . when should 20 men leave the work so that the entire work is completed in 40 days after they leave the work ? 
Options: a ) 22 days , b ) 10 days , c ) 77 days , d ) 88 days , e ) 55 days

Answer:
b