A pile of 52 tons of steel was transported, and 15.6 tons were transported in 3 hours. Based on this calculation, how many hours will it take to complete the transport? (Solution by proportional method)
运一堆52吨重的钢材，3小时运了15.6吨，照这样计算，还要几小时才能运完？(用比例方法解)
<gadget id="calculator">52 - 15.6</gadget>
<output>36.4</output>

<gadget id="calculator">15.6 / 3</gadget>
<output>5.2</output>

<gadget id="calculator">36.4 / 5.2</gadget>
<output>7</output>

<result>7</result>