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 cyclist bikes x distance at 20 miles per hour and returns over the same path at 16 miles per hour . what is the cyclist ' s average rate for the round trip in miles per hour ? 
Options: a ) 17.6 , b ) 17.3 , c ) 8.6 , d ) 17.2 , e ) 9.0
[A]: a


[Q]: Problem: a girl goes to her school from her house at a speed of 6 km / hr and returns at a speed of 4 km / hr . if she takes 10 hours in going and coming back , the distance between her school and house is 
Options: a ) 12 kms , b ) 16 kms , c ) 20 kms , d ) 24 kms , e ) none of above
[A]: d


[Q]: Problem: a man can do a piece of work in 5 days , but with the help of his son , he can finish it in 4 days . in what time can the son do it alone ? 
Options: a ) 5 , b ) 5 1 / 2 , c ) 7 1 / 2 , d ) 6 , e ) 20
[A]:
e