Rebecca wants to split a collection of eggs into 13 groups. Rebecca has 39 eggs and 21 marbles. How many eggs will each group have?
1. Rebecca wants to split a collection of eggs into 13 groups. 
2. She has 39 eggs and 21 marbles. 
3. How many eggs will each group have?

We can see that Rebecca has a total of 60 objects (39 eggs and 21 marbles). She wants to split them into 13 groups. This means that each group will have 60/13, or 4.6, objects. 

Since we can't have .6 of an egg, we'll round down and say that each group will have 4 eggs.