From a box containing 4 dimes and 2 nickels,3 coins are selected at random without replacement. Find the propability distribution for the total T of the 3 coins. Well, this was a simple matter of drawing out at tree diagram and writing everything out. The problem is that none of the statements the book make sense. They pulled these calculations from somewhere: 3 dimes: 4/6 * 3/5 * 2/4 = 1/5 2 dimes and a nickel: 3 * (4/6 * 3/5 * 2/4) = 3/5 1 dime and two nickels: 3 * (4/6 * 2/5 * 1/4) = 1/5 This just assumes all of the statements for a given outcome are the same. For instance, one of the 2D1N statements is incorrect. If you follow the path DDN you hit 4/6 for D, 2/5 for N, and then 3/4 for the final D. This makes even less sense because there are seven possible valid combinations, so therefore the distribution should be out of 7. Am I missing something here?