In a school there are w girls and the rest are boys. If there are x more girls than boys How many boys are there in that school?
There are w girls and the rest are boys.

This means that w = the total number of girls in the school, and the rest are boys. 

Therefore, the total number of students in the school is w + the rest. 

The question is asking for x more girls than boys. This means that w + x = the total number of girls in the school, and the rest are boys. 

Therefore, the total number of boys in the school is w - x.