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

Ex Input:
Problem: what is the total number of integers between 10 and 50 that are divisible by 2 ?

Ex Output:
19

Ex Input:
Problem: a family pays $ 800 per year for an insurance plan that pays 70 percent of the first $ 1,000 in expenses and 100 percent of all medical expenses thereafter . in any given year , the total amount paid by the family will equal the amount paid by the plan when the family ' s medical expenses total how much ?

Ex Output:
$ 1,400

Ex Input:
Problem: i bought two books ; for rs . 500 . i sold one at a loss of 15 % and other at a gain of 19 % and then i found each book was sold at the same price . find the cost of the book sold at a loss ?

Ex Output:
291.6