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

[Q]: Problem: in how many no . between 10 and 30 exactly two of the digits is 2 ?
[A]: 1


[Q]: Problem: when positive integer n is divided by 5 , the remainder is 1 . when n is divided by 7 , the remainder is 3 . what is the smallest positive integer k such that k + n is a multiple of 40 .
[A]: 7


[Q]: Problem: a sum of money at simple interest amounts to rs . 815 in 3 years and to rs . 878 in 4 years . the sum is :
[A]:
626