A bus and a car drive from station A to station B at the same time. After 4 hours, the bus traveled 360 kilometers and the car traveled 408 kilometers. On average, how many kilometers per hour is a bus slower than a car?
一辆大客车和一辆小轿车同时从甲站开往乙站，4小时后大客车行驶了360千米，小轿车行驶了408千米．大客车平均每小时比小轿车慢多少千米？
<gadget id="calculator">408 / 4</gadget>
<output>102</output>

<gadget id="calculator">360 / 4</gadget>
<output>90</output>

<gadget id="calculator">102 - 90</gadget>
<output>12</output>

<result>12</result>