Use two cars to jointly transport 54.6 tons of goods, and each car transports 6 times, just in time. It is known that the first car can transport 4.2 tons of goods each time, how many tons of goods can the second car transport each time?
用两辆汽车合运54.6吨货物，每辆车各运6次正好运完．已知第一辆汽车每次可运4.2吨货物，第二辆汽车每次可运多少吨货物？
<gadget id="calculator">4.2 * 6</gadget>
<output>25.2</output>

<gadget id="calculator">54.6 - 25.2</gadget>
<output>29.4</output>

<gadget id="calculator">29.4 / 6</gadget>
<output>4.9</output>

<result>4.9</result>