Car A travels 110 kilometers per hour, and car B travels 100 kilometers per hour. The two cars drive from two cities A and B at the same time. After 4 hours, the two cars meet on the way. When they meet, how many kilometers does B travel? rice?
甲车每小时行110千米，乙车每小时行100千米，两车分别从A、B两个城市同时相对开出，经过4小时两车在途中相遇，相遇时乙车行了多少千米？
<gadget id="calculator">100 * 4</gadget>
<output>400</output>

<result>400</result>