instruction:
The task is to generate the correct answer for a given math problem.
question:
Problem: the average of first 22 natural numbers is ?
answer:
11.5


question:
Problem: how much interest will $ 10,000 earn in 9 months at an annual rate of 4 % ?
answer:
$ 300


question:
Problem: if x / 4 years ago roger was 21 years old and x / 4 years from now he will be 4 x years old , how old will he be 5 x years from now ?
answer:

7