A car travels from A to B at 65 kilometers per hour and arrives in 6 hours. When returning from point B to point A, it takes 1 hour longer, what is the average speed of this car going back and forth?
一辆汽车从甲地开往乙地，每小时行65千米，6小时到达．从乙地返回甲地时，多用了1小时，求这辆汽车往返的平均速度？
<gadget id="calculator">6 + 1 + 6</gadget>
<output>13</output>

<gadget id="calculator">2 / 13</gadget>
<output>2/13 = around 0.153846</output>

<gadget id="calculator">65 * 6 * (2/13)</gadget>
<output>60</output>

<result>60</result>