Teachers and students repaired a batch of books together. Xiao Ming repaired 1/4 of the total number of books more than 3 books, Xiao Hong repaired 40% of the total number of books less than 2 books, Mr. Liu repaired 20 books, just finished repairing, how many books are there in total?
师生共同修补一批图书，小明修补了总数的(1/4)多3本，小红修补了总数的40%少2本，刘老师修补20本，刚好修完，问共有多少本？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">21 / (7/20)</gadget>
<output>60</output>

<result>60</result>