The school library bought 100 story books and science books, which cost a total of 2000 yuan. Can you fill in the figures in brackets in the table below according to these circumstances? storybook
(2000- 15×80)÷20,
=(2000- 1200)÷20,
=800÷20,
=40 yuan.
A: The average science and technology book is 40 yuan.
So the answer is: 40.