AP EAMCET Engineering 17 Sep 2020 Shift 2 Paper

The content of the 3 boxes are as follows. If One box is chosen at random and three balls are drawn from it and they are all of different colours, find the probability that they come from box 2?
▶ Box 1: contains 1 black, 2 white, 3 red balls, and
▶Box 2: contains 1 black, 1 white, 2 red balls, and
▶Box 3: has 5 black, 4 white, 1 red balls.