In the first part, where Bill tells Matt that he has three kids and the product of their ages as well as the sum, there are two possible combinations of ages that have the same sum; 3, 3, and 8, as well as 2, 6, and 6. However, once Bill says that he only has a youngest child, no two youngest children, we can eliminate 3, 3, and 8, and the ages are 2, 6, and 6.