Consider $3$ urns. Urn $A$ contains $2$ white balls and $4$ red balls; Urn $B$ contains $8$ white balls and $4$ red balls; Urn $C$ contains $1$ white ball and $3$ red balls. We draw $1$ ball from each Urn. What is the probability to draw a white ball from Urn $A$ if we know that we drew exactly a total of $2$ white balls total?
I am asked to proceed with Bayes theorem but i am a little confused on how to do it. Any hint would help me alot.