Please solve the question by Bayes theorem?

There are three urns containing black, red and green balls. urn 1 contains 4 black, 5 red and 3 green balls urn 2 contains 7 black, 4 red and 4 green balls urn three contains 6 black, 6 red and 5 green balls. An urn is chosen and ball is picked if the ball picked is green find the probability it has come from urn 3.