A certain factory needs to transport 73.5 tons of coal. It has been transported for 6 hours, with an average of 7.5 tons per hour, and the rest will be transported within 3 hours. How many tons per hour on average?
某工厂要运73.5吨煤，已经运了6小时，平均每小时运了7.5吨，剩下的要在3小时内运完，平均每小时运多少吨？
<gadget id="calculator">7.5 * 6</gadget>
<output>45</output>

<gadget id="calculator">73.5 - 45</gadget>
<output>28.5</output>

<gadget id="calculator">28.5 / 3</gadget>
<output>9.5</output>

<result>9.5</result>