7. (10 points) As shown in the figure, there are three identical plates on a circular tray. Xiao Xiao places 7 identical apples in these plates, with at least one apple in each plate. How many ways can Xiao Xiao place the apples? (Rotations of the tray that result in the same arrangement are considered the same.)


【Answer】Solution: By enumeration, we can get:
$(1,1,5) 、(1,2,4) 、(1,3,3) 、(1,4,2) 、(2,2,3)$, a total of 5;
Answer: Xiao Xiao has 5 ways to put the apples.
Therefore, the answer is: 5.