Xiao Ming reads a story book, if he reads 15 pages a day, he can finish it in 12 days. If you read 18 pages a day, how many days can you finish it? (Solution with proportional knowledge)
小明看一本故事书，如果每天看15页，12天可以看完．如果每天看18页，多少天可以看完？(用比例知识解)
<gadget id="calculator">15 * 12</gadget>
<output>180</output>

<gadget id="calculator">180 / 18</gadget>
<output>10</output>

<result>10</result>