2013 · Q3
In a school there are 30 teachers who teach Mathematics or Physics. Of these, 20 teach Mathematics and 15 teach Physics, 5 teach both Mathematics and Physics. The number of teachers teaching only Mathematics is
Elementary MathematicsSets
- A5
- B10
- C15
- D20
Explanation
Only Mathematics = 20 − 5 = 15. Answer C.