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

Input: Consider Input: Problem: the distance between a & b is 1540 km . a person is traveling from a to b at 100 km / hr started at 6 am and another person is traveling from b to a at 120 km / hr and started at same time . then at what time they meet together .

Output: 1 pm

Input: Consider Input: Problem: a swimmer can swim in still water at 4 km / h . if the speed of the water current is 2 km / h , how many hours will the swimmer take to swim against the current for 5 km ?

Output: 2.5

Input: Consider Input: Problem: a pharmaceutical company received $ 8 million in royalties on the first $ 20 million in sales of the generic equivalent of one of its products and then $ 9 million in royalties on the next $ 108 million in sales . by approximately what percent did the ratio of royalties to sales decrease from the first $ 20 million in sales to the next $ 108 million in sales ?
Output: 79