A car originally planned to travel from city A to city B in 6 hours. After driving half the distance, the car stopped for 30 minutes on the way for some reason. If you arrive at city B according to the original time, the speed of the car in the second half of the journey should be increased by 12 kilometers per hour, so how many kilometers are the distance between cities A and B?
一辆汽车原计划6小时从A城到B城．汽车行驶了一半路程后，因故在途中停留了30分钟．如果按照原定的时间到达B城，汽车在后一半路程的速度就应该提高12千米/时，那么A、B两城相距多少千米？
<gadget id="calculator">3 * 12</gadget>
<output>36</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 12</gadget>
<output>6</output>

<gadget id="calculator">36 - 6</gadget>
<output>30</output>

<gadget id="calculator">(1/2) - 3</gadget>
<output>-5/2 = around -2.5</output>

<gadget id="calculator">3 + (-5/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">30 / (1/2)</gadget>
<output>60</output>

<gadget id="calculator">60 * 6</gadget>
<output>360</output>

<result>360</result>