Question

There are 100 teachers in a school. 60 teach science, 25 teach humanities, 15 teach both science and humanities. 6Find the number of teachers who teach: (a) science but not humanities. (b) Humanities but not science. (c) Humanities or science.​

Answer 1

(a) 45

(b) 10

(c) 70

Explanation:

(a) The number of teachers who teach science but not humanities is:

Number who teach science - Number who teach both subjects

==> 60 - 15 = 45

(b) The number of teachers who teach humanities but not science is:

Number who teach humanities - Number who teach both subjects

==> 25 - 15 = 10

(c) The number who teach humanities or science is Number who teach humanities + number who teach science - number who teach both

60 + 25 - 15 = 70

There are 30 teachers who teach neither humanities nor science = 100 - 70