Question

In a school of 330 students, 85 of them are in a drama club, 200 of them are in a sports team and 60 of them do both

find the probability that the student isn't in a sports or drama club​

Answer 1

105/330 = 21/66 = 7/22

7/22 is the answer I think

Explanation:

n(U) = 330

n(A) = 85

n(B) = 200

n(A n B) = 60

Now,

n(A U B) = n(A) + n(B) - n(A n B)

or, n(A U B) = 85 + 200 - 60

or, n(A U B) = 285 - 60 = 225

Now,

n(A U B) compliment = n(U) - n(A U B)

n(A U B) compliment = 330 - 225

so, n(A U B) compliment = 105

Now,

probability = 105/330