Conditional Probability

Question

It is known that the event A and B are Mutually exclusive and that P(A)= 0.56 and P(B)=0.11

find P(A and B)?

Answer 1

This question is tricky. I guess it meant to test the understanding on “mutually exclusive” event.

If two events A and B are mutually exclusive, it means they can not happen at the same time. In another word, the chance for both event A and event B happening is 0.

Hence, P(A and B) = 0.

Note, P(A and B) is just a math way to ask what is the chance for both A and B happening; and another word for “mutually exclusive” is disjoint.

This question is tricky, because for this particular setting (mutually exclusive) we do not need the given info on P(A) and P(B) to find P(A and B).