I read 15 pages of a storybook every day, and I can finish it in 12 days. If you finish reading in 6 days, how many pages do you need to read each day?
一本故事书我每天读15页，12天就能读完．如果6天读完，每天要读多少页？
<gadget id="calculator">12 / 6</gadget>
<output>2</output>

<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<result>30</result>