a pile of coal. For the first time, 3 trucks transported 30 tons. The same number of trucks are used for the second time, and each truck transports 14 tons. How many tons of this pile of coal are transported by truck twice on average?
一堆煤．第一次3辆货车运走了30吨．第二次用同样多的货车，每辆货车运14吨．这堆煤两次平均每辆货车运多少吨？
<gadget id="calculator">14 * 3</gadget>
<output>42</output>

<gadget id="calculator">30 + 42</gadget>
<output>72</output>

<gadget id="calculator">3 + 3</gadget>
<output>6</output>

<gadget id="calculator">72 / 6</gadget>
<output>12</output>

<result>12</result>