The total length of a highway is 504 kilometers, and it takes 4.5 hours for a passenger car to complete the journey, and 4.8 hours for a truck to complete the journey. How much faster are passenger cars per hour than trucks per hour?
一条高速公路全长504千米，一辆客车4.5小时行完全程，一辆货车4.8小时行完全程．客车每小时比货车每小时的速度快多少？
<gadget id="calculator">504 / 4.5</gadget>
<output>112</output>

<gadget id="calculator">504 / 4.8</gadget>
<output>105</output>

<gadget id="calculator">112 - 105</gadget>
<output>7</output>

<result>7</result>