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: mariah has decided to hire three workers . to determine whom she will hire , she has selected a group of 12 candidates . she plans to have one working interview with 3 of the 12 candidates every day to see how well they work together . how many days will it take her to have working interviews with all the different combinations of job candidates ? 
Options: a ) 720 , b ) 120 , c ) 300 , d ) 30 , e ) 333
[EX A]: c

[EX Q]: Problem: it will take 16 days for mary to complete a certain task alone . she worked for 8 days before she was joined by her sister . both of them completed the remaining task in 2 and half days . if her sister had joined her when she started the task , how many days would it have taken ? 
Options: a ) 6 , b ) 8 , c ) 2 , d ) 5 , e ) 4
[EX A]: d

[EX Q]: Problem: the volume of a wall , 5 times as high as it is broad and 8 times as long as it is high , is 12.8 cu . meters . find the breadth of the wall . 
Options: ['a ) 40', 'b ) 29', 'c ) 28', 'd ) 27', 'e ) 12']
[EX A]:
a