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: today mary ' s father is 4 times as old as mary . 3 years ago , he was 5 times as old . how old is mary today ?
Options: a ) 6 , b ) 8 , c ) 10 , d ) 12 , e ) 14

Output: d

Input: Consider Input: 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

Output: b

Input: Consider Input: Problem: 6 workers should finish a job in 8 days . after 3 days came 4 workers join them . how many days z do they need to finish the same job ?
Options: a ) 3 , b ) 4 , c ) 5 , d ) 6 , e ) 7
Output: a