Assuming that the total number of seedlings is x, the number of seedlings taken in the first category is100+(x-100)10, and the number of seedlings taken in the second category is 200+[x-200-100-(x-/kloc-

100+(X- 100)/ 10 = 200+[X-200- 100-(X- 100)/ 10]/ 10

Solved:

X=8 100

That is, the total number of saplings is 8 100. Substituting100+(x-100)10, the number of saplings in the first class is 900.

According to the condition that the number of saplings in each category is equal, the number of categories can be listed as follows:

8 100÷900=9