MathDB

Urn A contains

4

white balls and

2

red balls. Urn B contains

3

red balls and

3

black balls. An urn is randomly selected, and then a ball inside of that urn is removed. We then repeat the process of selecting an urn and drawing out a ball, without returning the first ball. What is the probability that the first ball drawn was red, given that the second ball drawn was black?

Problem Statement