It takes 20 hours for the fast train to travel from A to B, and 30 hours for the slow train to travel from B to A. Two cars leave oppositely from two places at the same time. When they meet, the fast car travels 180 kilometers longer than the slow car. How many kilometers are the distance between A and B?
快车从甲地到乙地需要20小时，慢车从乙地到甲地需要30小时．两车同时从两地相对开出，相遇时快车比慢车多行180千米，甲、乙两地相距多少千米？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">180 / (1/5)</gadget>
<output>900</output>

<result>900</result>