# Conditional

The probability that event A occurs given that event B has already occurred is called conditional probability

This is denoted by P(A|B)

Sampling without replacement is a good example of conditional probability

If two events are independent then P(A|B) = P(B|A)

Two events are said to be conditional if the occurrence of one event is on the assumption that a previous event has already occurred

If two events are conditional then the probability of them both occurring is:

Example

What is the probability of pulling a diamond from a pack of cards and then subsequently pulling another diamond (assuming the first one is not returned to the pack).

A - the probability of pulling a diamond the first time

B - the probability of pulling a diamond the second time

P(A and B) = P(A) * P(B|A)

this is the multiplication rule

© 2022 Better Solutions Limited. All Rights Reserved. © 2022 Better Solutions Limited TopPrevNext