Sunshine Bookstore has a discount when buying books, as shown on the right. Lele bought a set of books which is cheaper than the original price. 36 yuan.

This is the final exercise of the sixth grade mathematics in the first semester of the 222-223 school year in Haidian District, Beijing. The title is the celebration of Sunshine Bookstore, and there is a discount for buying books, as shown on the right. Lele bought a set of books, which is cheaper than the original price. 36 yuan, how much is the original price of this set of books?

1. Find out the equivalence relation in the topic. You can draw a picture and write it.

2. List equations and solve problems.