A car traveled a total of 420 kilometers from 9 am to 4 pm. How many miles per hour on average?
一辆汽车从上午9时到下午4时共行了420千米．平均每小时行驶多少千米？
<gadget id="calculator">16 - 9</gadget>
<output>7</output>

<gadget id="calculator">420 / 7</gadget>
<output>60</output>

<result>60</result>