You are told that PA I B) = PBIA). Which statement below must be true?
O A and B are equally likely
O A and B are independent
O PAI B) = 0.5
A and B are dependent

A and B are equally likely

Explanation:

The conditional probability is defined as follows:

where:

is the probability for X to occur, given that Y has occurred

is the probability that both X and Y occur at the same time

is the probability for Y to occur

Given two events A and B, we have:

and

In this problem, we are told that

Which means that:

Simplifying, we get:

which means that A and B are equally likely.