A sock contains 2 red marbles and an unknown number of blue marbles. Tom places a new marble in the sock. Jason puts his hand in the sock and pulls out a red marble.
What is the probability that the marble Tom put in the sock was red?
I've been trying to approach this with Bayes' Theorem but not making any progress:
P(A l B) = P(B l A) * P(A) / P(B)
I'm confused as to what A and B would represent in the problem.
Appreciate the help, thanks!