Urn a contains 8 yellow balls and 6 red balls. urn b contains 3 yellow balls and 9 red balls. urn c contains 4 yellow balls and 11 red balls. an urn is picked randomly (assume that each urn is equally likely to be chosen), and then a ball is picked from the selected urn. what is the probability that the chosen ball came from urn b, given that it was a yellow ball? a) 0.2451 b) 0.0725 c) 0.2298 d) 0.0544 e) 0.5252 f) none of the above.