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: if 20 men can build a wall 112 metres long in 6 days , what length of a similar wall can be built by 30 men in 3 days ? 
Options: a ) 65 mtr . , b ) 84 mtr , c ) 70 mtr . , d ) 78 mtr . , e ) 17 mtr .
[A]: b


[Q]: Problem: the speed of a boat in still water is 20 km / hr and the rate of current is 5 km / hr . the distance travelled downstream in 27 minutes is : 
Options: a ) 9.25 , b ) 5.25 , c ) 7.25 , d ) 6.25 , e ) 11.25
[A]: e


[Q]: Problem: the speed at which a man can row a boat in still water is 15 km / hr . if he rows downstream , where the speed of current is 3 km / hr , how many seconds will he take to cover 90 meters ? 
Options: a ) 12 , b ) 16 , c ) 17 , d ) 18 , e ) 20
[A]:
d