Cars A and B drive oppositely from places A and B at the same time. When car A travels the whole distance (3/4) and car B travels the whole distance (2/5), the distance between the two cars is 30 kilometers. How far is the distance in kilometers?
甲、乙两车同时从A、B两地相对开出，当甲车行了全程的(3/4)，乙车行了全程的(2/5)时，两车相距30千米，两地的距离是多少千米？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

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

<gadget id="calculator">(2/5) - 1</gadget>
<output>-3/5 = around -0.6</output>

<gadget id="calculator">(3/4) + (-3/5)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">30 / (3/20)</gadget>
<output>200</output>

<result>200</result>