The distance between A and B is 800 kilometers. A passenger car runs from A to B, and a freight train runs from B to A at the same time. After 4 hours, the two cars meet. It is known that the truck travels 90 kilometers per hour, how many kilometers per hour does the passenger car travel?
甲乙两地相距800千米，一列客车从甲地开往乙地，同时有一列货车从乙地开往甲地，4小时后两车相遇．已知货车每小时行90千米，客车每小时行多少千米？
<gadget id="calculator">800 / 4</gadget>
<output>200</output>

<gadget id="calculator">200 - 90</gadget>
<output>110</output>

<result>110</result>