Two cars drive from two places 4000 meters apart at the same time, and meet after 40 minutes. Car A travels 45 meters per minute, and car B travels how many meters per minute.
两辆车同时从相距4000米的两地相对开出，40分后相遇，甲车每分行驶45米，乙车每分行驶多少米．
<gadget id="calculator">4_000 / 40</gadget>
<output>100</output>

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

<result>55</result>