Marvin randomly places 7 Scuba Steve action figures and 6 Diving Dan action figures in
4 distinguishable boxes. If each box must have at least one of each type of action figure, how
many ways can Marvin do this?
First, to ensure that each box must have one of each type, Marvin could place one of each type into each box before he starts randomizing the contents.
After he does so, there are 3 Scuba Steve figures and 2 Diving Dan figures left. Now he can place the figures into the boxes as usual, ignoring the constraints.
Is this easier now?