Cars A, B, and C start from point A to point B at the same time. Vehicles A and B are traveling at 90 and 72 kilometers per hour respectively. An oncoming truck encounters vehicles A, B and C successively 6 hours, 7 hours and 8 hours after their departure. So, how many kilometers does car C travel per hour?
甲、乙、丙三辆车同时从A地出发到B地去．甲、乙两车每小时的速度分别为90、72千米，有一辆迎面开来的卡车在他们出发后6小时、7小时、8小时先后与甲、乙、丙三辆车相遇．那么，丙车每小时行多少千米．
<gadget id="calculator">90 * 6</gadget>
<output>540</output>

<gadget id="calculator">108 - 72</gadget>
<output>36</output>

<gadget id="calculator">36 * 2</gadget>
<output>72</output>

<gadget id="calculator">540 - 72</gadget>
<output>468</output>

<gadget id="calculator">468 / 8</gadget>
<output>117/2 = around 58.5</output>

<result>117/2 = around 58.5</result>