400
In a certain college, 40% of the senior class students is taking Physics, 30% is taking calculus and 10% is taking both. If 40 students are enrolled in the senior class, how many students are taking neither Physics nor calculus?
16 students
Explanation
I want to count the 10% that take both courses only once,
so I will include them in the 40% that take Physics,
but not in the 30% that take calculus.
Therefore I have counted 40% + (30% - 10%) = 60%
of the students.
60% of 40= 24 and 40-24=16