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

[EX Q]: Problem: income and expenditure of a person are in the ratio 7 : 6 . if the income of the person is rs . 14000 , then find his savings ?
[EX A]: 2000

[EX Q]: Problem: find the least number must be subtracted from 62575 so that remaining number is divisible by 99 .
[EX A]: 7

[EX Q]: Problem: a certain protective additive increases from 30 days to 45 days the time between required maintenance checks on an industrial vehicle . by what percent is the time between maintenance checks increased by using the additive ?
[EX A]:
50 %