The school library bought 240 more books this year than last year, and the number of books bought last year was 75% of this year. How many books did you buy this year and last year?
The number of books bought last year is 75% that of this year.
This year's purchases are 4/3 of last year's, an increase of 1/3.
240÷ 1/3=720 (Ben),
720+240=960 (Ben)
A: I bought 960 copies this year and 720 copies last year.