The task is to generate the correct answer for a given math problem.

[Q]: Problem: a can do a work in 15 days and b in 20 days . if they work on it together for 7 days , then the fraction of the work that is left is
[A]: 11 / 6


[Q]: Problem: if shares of two persons in profits are rs . 600 and rs . 1000 then ratio of their capitals is
[A]: 3 : 5


[Q]: Problem: two equally sized jugs full of water are each emptied into two separate unequally sized empty jugs , x and y . now , jug x is 1 / 5 full , while jug y is 4 / 7 full . if water is poured from jug x into jug y until jug y is filled , what fraction of jug x then contains water ?
[A]:
1 / 20