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'.

Input: Consider Input: Problem: a train overtakes two person who are walking in the same direction in which the train is going , at the rate of 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively . the length of the train is :
Options: a ) 45 m , b ) 50 m , c ) 54 m , d ) 72 m , e ) none of these

Output: b

Input: Consider Input: Problem: a water tank is four - fifths full . pipe a can fill a tank in 10 minutes and pipe b can empty it in 6 minutes . if both the pipes are open , how many minutes will it take to empty or fill the tank completely ?
Options: a ) 6 , b ) 9 , c ) 10 , d ) 12 , e ) 15

Output: d

Input: Consider Input: Problem: a and b can do a work in 12 days and 36 days respectively . if they work on alternate days beginning with b , in how many days will the work be completed ?
Options: a ) 11 , b ) 17 , c ) 10 , d ) 17 , e ) 18
Output: e