Find the probability that he attends at least one of those classes.

Question

A student attends mathematics class with probability of 65%. He attends drama class with probability of 85%. If attending those classes are independent, find the probability that he attends at least one of those classes.

Answer 1

Hi Alana

 

The probability that the student attends at least one of these classes is equal to 

1 - the probability that the student attends none of these classes.

 

If P(M) = .65, then P(~M) = .35  where ~ means not

If P(D) = .85, then P(~D) = .15

 

Then P(~M ∩ ~D) = .35 x .15 = .0525

 

And P(attending at least one class) = 1-.0525 = .9475 = 94.75%