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: a cistern is normally filled in 10 hrs , but takes 2 hrs longer to fill because of a leak on its bottom , if cistern is full , how much time citern would empty ? 
Options: a ) 10 hours , b ) 20 hours , c ) 60 hours , d ) 40 hours , e ) 50 hours
[A]: c


[Q]: Problem: 45 men working 8 hours per day dig 40 m deep . how many extra men should be put to dig to a depth of 50 m working 6 hours per day ? 
Options: a ) 10 , b ) 20 , c ) 30 , d ) 40 , e ) 50
[A]: c


[Q]: Problem: a man rows his boat 78 km downstream and 50 km upstream , taking 2 hours each time . find the speed of the stream ? 
Options: a ) 76 kmph , b ) 6 kmph , c ) 14 kmph , d ) 7 kmph , e ) 4 kmph
[A]:
d