Step 1 :The sample space consists of all the possible outcomes. In this case, the man can choose between two sizes (10-foot and 12-foot) and three colors (black, sky blue, and rust). Therefore, the total number of outcomes is 2 * 3 = 6.
Step 2 :For part (a), there is only one outcome where he buys a 12-foot sky blue umbrella, so the probability is \(\frac{1}{6}\).
Step 3 :For part (b), there are three outcomes where he buys a 10-foot umbrella (one for each color), so the probability is \(\frac{3}{6} = \frac{1}{2}\).
Step 4 :For part (c), there are two outcomes where he buys a black-colored umbrella (one for each size), so the probability is \(\frac{2}{6} = \frac{1}{3}\).
Step 5 :Final Answer: (a) The probability that he buys a 12-foot sky blue umbrella is \(\boxed{\frac{1}{6}}\). (b) The probability that he buys a 10-foot umbrella is \(\boxed{\frac{1}{2}}\). (c) The probability that he buys a black-colored umbrella is \(\boxed{\frac{1}{3}}\).