There were 100 visitors in a library on a particular day of them 28 had taken only Mathematics book. 30 had taken Physics book. 42 had taken Chemistry book. 8 had taken Mathematics and Physics 5 had taken Chemistry and Mathematics 8 had taken Physics and Chemistry 3 had taken all three subject. Find the number of students taken only two book.
answer
39
explanation
15=students who took maths
14=students who took physics
29=students who took chemistry
3=students who took all three
totally 61.
total no.of students-no.of .visitors per day .
=39