A rides a bicycle from point A to point B at 16 kilometers per hour. One hour later, B also rode a bicycle from point A to point B, traveling 20 kilometers per hour, and they both arrived at point B at the same time. How many kilometers are there between A and B?
甲骑自行车从A地到B地，每小时行16千米．1小时后，乙也骑自行车从A地到B地，每小时行20千米，结果两人同时到达B地．A、B两地相距多少千米？
<gadget id="calculator">20 - 16</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">16 * (1/4)</gadget>
<output>4</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<result>80</result>