Without a visual of the tree diagram mentioned in the problem, it is difficult to provide an exact answer. However, we can use the fundamental counting principle to determine the number of possible combinations.
If there are, for example, 4 colors of balloons and 5 types of toys, then the number of different combinations a child may receive would be:
4 (number of colors) x 5 (number of types of toys) = 20
Therefore, the child may receive 20 different combinations of one color of balloon and one type of toy. However, this number may vary depending on the actual number of colors and types of toys available.