P(bolw #1) = 1/2
if #1, P(choc) = 10/50
See what you can do with that, knowing what you do about conditional probabilities.
Suppose there are two full bowls of cookies. Bowl #1 has 10 chocolate chip and 40 oatmeal, while bowl #2 has 30 chocolate chip cookies and 20 oatmeal cookies. Our friend Bob picks a bowl at random, and then picks a cookie at random. We may assume there is no reason to believe Bob treats one bowl differently from another, likewise for the cookies. The cookie turns out to be a oatmeal one. How probable is it that Bob picked it out of Bowl #2?
1 answer