How many students like exactly one of the genres?
A campus radio station surveyed 190 students to determine the genres of music they liked. The survey results follow:
114 like rock
50 like country
15 like rock and rap
11 like rap and country
20 like rap only
10 like rock and rap, but not country
9 like rock and country, but not rap
20 don't like any of the three types of music.