total of 18.6 tons of goods were transported by a truck three times. The first shipment was 5.15 tons, the third shipment was 4.93 tons, how many tons was the second shipment?
一辆卡车三次共运货18.6吨．第一次运5.15吨，第三次运了4.93吨，第二次运了多少吨？
<gadget id="calculator">18.6 - 5.15 - 4.93</gadget>
<output>8.52</output>

<result>8.52</result>