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

[Q]: Problem: what is the units digit of 26 ! + 50 ! + 4 ! + 4 ! ?
[A]: 8

[Q]: Problem: 33 1 / 3 % of 36 ?
[A]: 12 number

[Q]: Problem: the average monthly income of p and q is rs . 2050 . the average monthly income of q and r is rs . 5250 and the average monthly income of p and r is rs . 6200 . the monthly income of r is :
[A]:
9400