The distance between A and B is 500 kilometers. The fast and slow cars drive from the two places at the same time. After 5 hours, the two cars meet. The fast car travels 55 kilometers per hour. Find the speed of the slow car.
甲、乙两地相距500千米，快、慢两车同时从两地相向开出，5小时后两车相遇，快车每小时行55千米，求慢车的速度．
<gadget id="calculator">500 / 5</gadget>
<output>100</output>

<gadget id="calculator">100 - 55</gadget>
<output>45</output>

<result>45</result>