The distance between A and B is 290 kilometers. A car drives from A to B. After driving for 6 hours, it is still 50 kilometers away from B. How many kilometers per hour does the car travel on average?
甲乙两地相距290千米，一辆汽车从甲地开往乙地，行了6小时后，离乙地还有50千米．汽车平均每小时行多少千米？
<gadget id="calculator">290 - 50</gadget>
<output>240</output>

<gadget id="calculator">240 / 6</gadget>
<output>40</output>

<result>40</result>