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

Problem: how many prime numbers are between 51 / 13 and 89 / 9 ?
2

Problem: the average weight of a group of boys is 30 kg . after a boy of weight 45 kg joins the group , the average weight of the group goes up by 1 kg . find the number of boys in the group originally ?
14

Problem: a number whose fifth part increased by 5 is equal to its fourth part diminished by 5 is ?

200

