In one year, a school uses 13,270 pieces of white paper, 7,570 fewer pieces of blue paper than white paper, and 1,600 fewer pieces of yellow paper than blue paper. how many pieces of paper does the school use in all?

The school uses 23,070 pieces of paper in all.

Here's an explanation:

It is already given that the school uses 13,270 pieces of white paper. Then it says that there are 7,570 fewer pieces of blue paper than white paper. So if you subtract 7,570 from 13,270, you get that the school used 5700 pieces of blue paper. Then it says that there are 1,600 fewer pieces of yellow paper than blue paper. So when you subtract 1,600 from 5,700, you get that the school used 4,100 pieces of yellow paper. So if you do 13,270+5,700+4,100, you get that the school used 23,070 pieces of paper in total.