Question

4. In a school of 120 students, 41 studied Maths, 48 studied Chemistry and 42 studied Physics, 16 studied both Chemistry and Maths, 14 studied Maths and Physics, 18 studied Chemistry and Physics and 9 studied all the three subjects. Find how many of them studied:

(i) Exactly one subject.
(ii) At least one subject.
(iii) None of the subjects

Answer 1

i) 62

ii) 92

iii) 28

Explanation:

i) 19+23+20

=62

ii) 23+9+9+7+19+5+20

=92

iii) 120-23-9-9-7-19-5-20

or

120-92

=28