pile of coal is planned to burn 3.6 tons per day, which can be burned for 28 days. Actually burn 2.4 tons per day, how many days did this pile of coal burn? (Solve with ratio)
一堆煤，计划每天烧3.6吨，可烧28天．实际每天烧2.4吨，这堆煤烧了多少天？(用比例解)
<gadget id="calculator">28 / 2.4</gadget>
<output>11.666667</output>

<gadget id="calculator">3.6 * 11.666667</gadget>
<output>42.000001</output>

<result>42.000001</result>