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

Input: Consider Input: Problem: by selling an article for $ 225 a person gains $ 75 . what is the gain % ?

Output: 50 %

Input: Consider Input: Problem: in a village of 2,500 people , 800 people are over 70 years old and 850 people are female . it is known that 40 percent of the females are younger than 70 years old . if no one in the village is 70 years old , what is the probability that a person chosen at random is either a male or younger than 70 years old ?

Output: 199 / 250

Input: Consider Input: Problem: if each participant of a chess tournament plays exactly one game with each of the remaining participants , then 276 games will be played during the tournament . find the number of participants .
Output: 24