Three vehicles A, B, and C start from A to B at the same time, and the speeds of A and B are 60 kilometers and 48 kilometers per hour respectively. There is an oncoming truck that encounters vehicles A, B, and C successively 6 hours, 7 hours, and 8 hours after they set off. Find the speed of car C in km/h.
甲、乙、丙三辆车同时从A地出发到B地去，甲、乙两车的速度分别为每小时60千米和48千米．有一辆迎面开来的卡车分别在他们出发后6小时、7小时、8小时先后与甲、乙、丙三辆车相遇．求丙车的速度是多少千米/小时．
<gadget id="calculator">60 - 48</gadget>
<output>12</output>

<gadget id="calculator">7 - 6</gadget>
<output>1</output>

<gadget id="calculator">6 / 1</gadget>
<output>6</output>

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

<gadget id="calculator">72 - 48</gadget>
<output>24</output>

<gadget id="calculator">48 + 24</gadget>
<output>72</output>

<gadget id="calculator">72 / 8</gadget>
<output>9</output>

<gadget id="calculator">48 - 9</gadget>
<output>39</output>

<result>39</result>