The distance between A and B is 400 kilometers. A passenger car and a truck drive towards each other at the same time. After (the smallest composite number) hours, they meet. It is known that the passenger car travels 55 kilometers per hour, and the truck travels thousands of kilometers per hour. rice?
甲乙两地相距400千米，一辆客车和一辆货车同时从两地相向而行，经过(最小的合数)个小时相遇，已知客车每小时行55千米，货车每小时行多少千米？
<gadget id="calculator">400 / 4</gadget>
<output>100</output>

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

<result>45</result>