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'.

[Q]: 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
[A]: d


[Q]: Problem: if 36 men can do a piece of work in 5 hours , in how many hours will 15 men do it ? 
Options: a ) 12 , b ) 38 , c ) 60 , d ) 88 , e ) 72
[A]: a


[Q]: Problem: in a kilometer race , a beats b by 48 meters or 12 seconds . what time does a take to complete the race ? 
Options: a ) 238 sec , b ) 190 sec , c ) 667 sec , d ) 167 sec , e ) 176 sec
[A]:
a