Students in three classes of the fifth grade help the library to repair books. The first class repaired 54 books, the second class repaired the first class (8/9), the third class repaired less than the second class (1/6), how many books did the third class repair?
五级三个班学生帮助图书室修补图书．一班修补了54本，二班修补的是一班的(8/9)，三班修补的比二班少(1/6)，三班修补了多少本？
<gadget id="calculator">8 / 9</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">54 * (8/9) * (5/6)</gadget>
<output>40</output>

<result>40</result>