Answer: Suppose this workbook is X sheets of paper, and Xiao Liang bought Y sheets of paper.

Can you get X+30=Y from the title? X+ 10=(25/30)Y, two equations can be obtained at the same time, X=90 (Zhang) Y= 120 (Zhang).

So this workbook is 90 sheets of paper, and Xiao Liang bought 120 sheets of paper.

A: This workbook has 90 sheets of paper.