From A to B, Xiaohua rides 1/3 of the bicycle and 2/3 of the car; from B to A, rides 3/5 of the bicycle and 2/5 of the car, and the result is half an hour slower. It is known that cycling is 12 kilometers per hour, and driving is 30 kilometers per hour. Ask: How many kilometers are there between A and B?
小华从甲地到乙地，3分之1骑车，3分之2乘车；从乙地返回甲地，5分之3骑车，5分之2乘车，结果慢了半小时．已知，骑车每小时12千米，乘车每小时30千米，问：甲乙两地相距多少千米？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(3/5) * (1/12)</gadget>
<output>1/20 = around 0.05</output>

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

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(2/5) * (1/30)</gadget>
<output>1/75 = around 0.013333</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) * (1/12)</gadget>
<output>1/36 = around 0.027778</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/3) * (1/30)</gadget>
<output>1/45 = around 0.022222</output>

<gadget id="calculator">(1/75) - (1/36) - (1/45)</gadget>
<output>-11/300 = around -0.036667</output>

<gadget id="calculator">(1/20) + (-11/300)</gadget>
<output>1/75 = around 0.013333</output>

<gadget id="calculator">0.5 / (1/75)</gadget>
<output>37.5</output>

<result>37.5</result>