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'.

[EX Q]: Problem: stacy has a 81 page history paper due in 3 days . how many pages per day would she have to write to finish on time ? 
Options: a ) 9 , b ) 27 , c ) 10 , d ) 8.5 , e ) 6
[EX A]: b

[EX Q]: Problem: 63 men working 8 hours per day dig 30 m deep . how many extra men should be put to dig to a depth of 50 m working 6 hours per day ? 
Options: a ) a ) 87 , b ) b ) 77 , c ) c ) 66 , d ) d ) 55 , e ) e ) 97
[EX A]: b

[EX Q]: Problem: a , b and c can do a piece of work in 9 days , 14 days and 28 days respectively . how long will they taken , if all the three work together ? 
Options: a ) 4.12 days , b ) 4.52 days , c ) 3.52 days , d ) 2.52 days , e ) 4.92 days
[EX A]:
b