Divide 99 students into 10 groups. These groups are divided into two categories: sports group 12 people and calligraphy group with 5 people.

Hello, there are X groups in the calligraphy group and Y groups in the sports group.

5x+ 12y=99

Here we take y= 1, 2, 3 ... and find X. If X is a positive number, the answer comes out. Speaking of x

Give up when y= 1 and x=87/5.

When y=2, x= 15.

Push it down in the same way

The final answer is that there are two situations. The first one is y=2 and x= 15. The second is y=7 and x=3.

I hope it helps you. .