Two cars drive from A and B at the same time. Car A travels 80 kilometers per hour, and car B travels 90 kilometers per hour. The two cars meet at a distance of 20 kilometers from the midpoint. What is the distance in kilometers between A and B?
两辆汽车从A、B两地同时相对开出，甲车每小时行80千米，乙车每小时行90千米，两车在离中点20千米处相遇．求A、B两地的距离是多少千米？
<gadget id="calculator">80 + 90</gadget>
<output>170</output>

<gadget id="calculator">90 - 80</gadget>
<output>10</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">20 * (1/5)</gadget>
<output>4</output>

<gadget id="calculator">170 * 4</gadget>
<output>680</output>

<result>680</result>