in one elementary school class the following information on sports preferences was obtained: 7 liked tennis; 11 liked baseball; 9 liked soccer; 5 liked tennis and baseball; 3 liked baseball and soccer; 2 liked tennis and soccer; and 2 liked all three sports. How many students liked either tennis or soccer?

3 answers

Hint:
Draw a Venn diagram to fill in all the numbers, starting with the last (2 liked all sports) and work backwards.
I find 17 students in all.

Not too sure how the question is supposed to be interpreted:
1. how many students liked tennis and no other sport or soccer and no other sport? (5)
2. how many students liked at least one of tennis or soccer? (13)
14
13