A car travels for 2 hours in the morning and 5 hours in the afternoon at the same speed, and travels 156 kilometers longer in the afternoon than in the morning. How many miles per hour does the car travel on average?
一辆汽车上午行2小时，下午用同样的速度行5小时，下午比上午多行156千米．这辆汽车平均每小时行多少千米？
<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">156 / 3</gadget>
<output>52</output>

<result>52</result>