The road from Hongxing Village to the county seat is 158 km long. A car drives from Hongxing Village to the county seat. After driving for 3 hours, it is still 8 km away from the county seat. How many kilometers per hour does this car travel on average?
红星村到县城公路长158km，一辆汽车从红星村开往县城，开出3小时后离县城还有8km，这辆汽车平均每时行多少km？
<gadget id="calculator">158 - 8</gadget>
<output>150</output>

<gadget id="calculator">150 / 3</gadget>
<output>50</output>

<result>50</result>