A car travels from place A to place B at a speed of 78 km/h. It takes 12 hours and it takes 1 hour longer to return. How many kilometers per hour will it travel when returning?
一辆汽车以78千米/小时的速度从甲地开往乙地，用去12小时，返回时多用了1小时，返回时每小时行多少千米？
<gadget id="calculator">12 + 1</gadget>
<output>13</output>

<gadget id="calculator">12 / 13</gadget>
<output>12/13 = around 0.923077</output>

<gadget id="calculator">78 * (12/13)</gadget>
<output>72</output>

<result>72</result>