UIUC An urn contains 4 balls: 1 white, 1 green and 2 red. We draw 3 balls with replacement. Find the probability that we did not see all three colors. Use two different calculations, as specified by (a) and (b) below. (a) Define the event W = {white ball did not appear} and similarly for G and R. Use inclusion-exclusion. (b) Compute the probability