Preview 1

A. Think of this as selecting combinations with repetition. We have 5 types, (the children). First the chocolate bars. We ask, how many ways are there to select 20 children’s names from a set of 5 different names (types). This is just 20+5 1 20. Same for the gum. Pick 15 children’s names from the 5 different names: 15+5 1 15.
Preview 1
Preview 2
Preview 3
Preview 4
Preview 5
Preview 6