1. (3 points) Coloring rocks Six rocks are sitting in a straight line. We paint them, using up to three colors (say, R's, W's, and B's). Suppose all of the 36 = 729 outcomes are equally likely. (a) (1 point) Find the probability that exactly 1 color of paint is used. (b) (1 point) Find the probability that exactly 2 colors of paint are used. (c) (1 point) Find the probability that all 3 colors of paint are used