Question

There are 219 people at the science camp. 112 people are enrolled in the chemistry class, and 45 people are enrolled in the physics class. How many students are enrolled in both classes if 79 students are not enrolled in either of them?

Answer 1

The correct answer is - 17.

Explanation:

Given:

total students = 219

in chemistry = 112

in physics = 45

not enrolled in either of these = 79

solution:

The number of students in both classes can be calculated by

P ( A or B) = P (A) + P (B) - P (A and B)

then putting and solving the given vaues in formula

=> (219-79) = 112+45-x

=> 140 = 157 -x

=> 17 = x