Find the number of ways of selecting 9 balls from 6 red balls, 5 white balls and 5 blue balls if each selection consists of 3 balls of each color.
In how many ways can 4 balls be selected from a box containing 1 red, 2 blue, 3 white and 4 black balls such that at least two selected balls are of the same colour? It is known that all the balls of a colour are identical. ___