In a class of 140 students numbered 1 to 140, all even numbered students opted Mathematics course, those whose number is divisible by 3 opted Physics course and those whose number is divisible by 5 opted Chemistry course. Then the number of students who did not opt for any of the three courses is
We know,
According to question.
Let no. of students opted maths = = 70
student opted physics = = 40
student opted chemistry = = 28
Therefore, total no. of student not adopting any course = total -