Dongdong reads a storybook. If he reads 12 pages a day, he can finish it in 15 days. If he wants to finish it in 9 days, how many pages do he read on average every day?
东东看一本故事书，如果每天看12页，15天能看完，如果想9天看完，平均每天看多少页？
<gadget id="calculator">15 / 9</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">12 * (5/3)</gadget>
<output>20</output>

<result>20</result>