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: calculate the speed of a boat in still water ( in km / hr ) if in one hour , the boat goes 10 km / hr downstream and 4 km / hr upstream . 
Options: a ) 7 kmph , b ) 8 kmph , c ) 9 kmph , d ) 7 kmph , e ) 6 kmph
[A]: a


[Q]: Problem: a contractor undertakes to built a walls in 50 days . he employs 20 peoples for the same . however after 25 days he finds that only 40 % of the work is complete . how many more man need to be employed to complete the work in time ? 
Options: a ) 25 , b ) 30 , c ) 35 , d ) 30 , e ) none of these
[A]: d


[Q]: Problem: 8 : 4 seconds : : ? : 4 minutes 
Options: a ) 10 , b ) 8 , c ) 20 , d ) 25 , e ) 30
[A]:
b