If a pile of coal burns 3.6 tons per day, it can be burned for 30 days. If it burns 2.4 tons per day, how many days can it be burned?
一堆煤每天烧3.6吨，可以烧30天，如果每天烧2.4吨，可以烧几天？
<gadget id="calculator">30 / 2.4</gadget>
<output>12.5</output>

<gadget id="calculator">3.6 * 12.5</gadget>
<output>45</output>

<result>45</result>