A and B travel between places A and B. A travels from A and B travels towards each other at the same time, and they meet on the way. A travels 10 kilometers per hour, and B travels 8 kilometers per hour. They return immediately after arriving at the starting point of the other party. The distance between the first meeting point and the second meeting point is 20 kilometers. Find the distance between A and B ?
甲乙两人往返于A、B两地之间，甲从A，乙从B同时相向而行，途中相遇．甲每小时行10千米，乙每小时行8千米，各自到达对方出发地后立即返回，第一次相遇与第二次相遇点之间相距20千米，求A、B之间的距离？
<gadget id="calculator">10 + 8</gadget>
<output>18</output>

<gadget id="calculator">10 - 8</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

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

<gadget id="calculator">18 * 5</gadget>
<output>90</output>

<result>90</result>