Question

In a survey, there were 109 students who like to play Candy Crush, 19 like Flappy Bird, and 127 like DOTA. 19 like to play Candy Crush and DOTA, 17 like Flappy Bird and DOTA, 30 like Candy Crush and Flappy Bird. If there are 15 students who like to play all:
1. How many like Candy Crush only?
2. How many like DOTA only?
3. How many like Flappy Bird only?
4. How many students were surveyed?

Answer 1

1: 109 students
2: 127 students