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

[Q]: Problem: how many quarters are equal to 7 dollars ?
[A]: 28


[Q]: Problem: the length of a rectangle is increased by 15 % and its breadth is decreased by 20 % . what is the effect on its area ?
[A]: 920


[Q]: Problem: george does 3 / 5 th of a piece of work in 9 days . he then calls in paul and they finish the work in 4 days . how long would paul take to do the work by himself ?
[A]:
30