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

[EX Q]: Problem: a and b are 90 km apart they start to move each other simultaneously a at speed 10 and b at 5 km / hr if every hour they double their speed what is distance that a pass until he meet b ?
[EX A]: 60 km

[EX Q]: Problem: a can do a piece of work in 80 days . he works at it for 10 days b alone finishes the remaining work in 42 days . in how much time will a and b working together , finish the work ?
[EX A]: 30

[EX Q]: Problem: the ratio between the length and the breadth of a rectangular plot is 7 : 5 . if the perimeter of the plot is 288 metres , what is its area ?
[EX A]:
5040 sq . metres', 'e ) none of these'