Li Xiaolin read a story book. If you read 12 pages a day, you can finish it in 15 days. If you want to read it in 10 days, how many pages should you read on average per day?
李小林看一本故事书．如果每天看12页，15天刚好看完．如果要10天看完，平均每天应该看多少页？
<gadget id="calculator">12 * 15</gadget>
<output>180</output>

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

<result>18</result>