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

[Q]: Problem: find compound interest on $ 10000 at 15 % per annum for 2 years 4 months , compounded annually .
[A]: 3886.25

[Q]: Problem: what is the sum of the multiples of 4 between 63 and 151 inclusive ?
[A]: 233

[Q]: Problem: a library has an average of 510 visitors on sundays and 240 on other day . the average number of visitors in a month of 50 days starting with sunday is
[A]:
171