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: it will take 16 days for mary to complete a certain task alone . she worked for 8 days before she was joined by her sister . both of them completed the remaining task in 2 and half days . if her sister had joined her when she started the task , how many days would it have taken ? 
Options: a ) 6 , b ) 8 , c ) 2 , d ) 5 , e ) 4
[A]: d


[Q]: Problem: a pipe can fill a cistern in 33 minutes . find the time in which 1 / 11 part of the cistern will be filled ? 
Options: a ) 5 min , b ) 2 min , c ) 3 min , d ) 1 min , e ) 10 min
[A]: c


[Q]: Problem: a man can row upstream at 26 kmph and downstream at 30 kmph , and then find the speed of the man in still water ? 
Options: a ) 29 , b ) 28 , c ) 30 , d ) 32 , e ) 23
[A]:
b