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: two pipes a and b can separately fill a tank in 12 and 20 minutes respectively . a third pipe c can drain off 45 liters of water per minute . if all the pipes are opened , the tank can be filled in 15 minutes . what is the capacity of the tank ? 
Options: a ) 542 , b ) 540 , c ) 675 , d ) 829 , e ) 279
[A]: c


[Q]: Problem: two pipes a and b can separately fill a cistern in 24 minutes and 48 minutes respectively . there is a third pipe in the bottom of the cistern to empty it . if all the three pipes are simultaneously opened , then the cistern is full in 12 minutes . in how much time , the third pipe alone can empty the cistern ? 
Options: a ) 90 min , b ) 48 min , c ) 54 min , d ) 120 min , e ) 130 min
[A]: b


[Q]: Problem: if 15 men , working 9 hours a day , can reap a field in 16 days , in how many days will 18 men reap the field , working 8 hours a day ? 
Options: a ) 10 , b ) 15 , c ) 20 , d ) 25 , e ) none of them
[A]:
b