Answer:
11 mushrooms
Step-by-step explanation:
Let's take two sets of numbers that fulfill the requirements (2 and 24 | 5 and 27)
In the first case, there are 26 mushrooms, and to have an equal amount they each need 13. Collin had to give 11 mushrooms to Sophie.
In the second case, there are 32 mushrooms, and they both need 16 each. So in this case, Collin also had to give 11 to Sophie.
The answer is 11 mushrooms.
