A certain county is 567km away from Zhengzhou. Manager Zhang drove from the county to Zhengzhou for work at 8:00 a.m. and arrived in Zhengzhou at 3:00 p.m. How many kilometers per hour does Manager Zhang drive on average?
某县城距郑州567km，张经理上午8时驾车从县城出发到郑州办事，下午3时赶到郑州．张经理驾车平均每时行驶多少千米？
<gadget id="calculator">15 - 8</gadget>
<output>7</output>

<gadget id="calculator">567 / 7</gadget>
<output>81</output>

<result>81</result>