Xiao Ming reads a book, if he reads 24 pages a day, he can finish it in 25 days; if he reads 20 pages a day, how many days can he finish it? (Solve with ratio)
小明看一本书，若每天看24页，25天看完；若每天看20页，几天可以看完？(用比例解)
<gadget id="calculator">24 * 25</gadget>
<output>600</output>

<gadget id="calculator">600 / 20</gadget>
<output>30</output>

<result>30</result>