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

Problem: bob wants to run a mile in the same time as his sister . if bob ' s time for a mile is currently 11 minutes 20 seconds and his sister ' s time is currently 9 minutes 36 seconds , by what percent does bob need to improve his time in order run a mile in the same time as his sister ?
15

Problem: what is the diagonal of a square field whose perimeter is 64 m ?
16 2 m

Problem: the roof of an apartment building is rectangular and its length is 3 times longer than its width . if the area of the roof is 588 feet squared , what is the difference between the length and the width of the roof ?
28 .