Xiao Ming reads a book. If he reads 15 pages a day, he can finish it in 24 days. If he reads 20 pages a day, how many days can he finish it?
小明看一本书，如果每天看15页，24天看完，如果每天看20页，几天可以看完？
<gadget id="calculator">15 / 20</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">24 * (3/4)</gadget>
<output>18</output>

<result>18</result>