I happened to come across these two probability questions in a library book. 1) Suppose that you roll 5 six-sided dice at the same time. What is the probability of getting a sum of 20? 2) Suppose that you roll a six-sided die 5 times. What is the probability of getting a sum of 20 on the 5 rolls? What is the difference between these two problems? What methods are used to solve them?