A plane is flying from A to B. It originally planned to fly 9 kilometers per minute, but now it is flying at a speed of 12 kilometers per minute. The result is that it arrives half an hour earlier than the original plan. How many kilometers are there between A and B?
一架飞机从甲地开往乙，原计划每分钟飞行9千米，现在按每分钟12千米的速度飞行，结果比原计划提前半小时到达，甲、乙两地相距多少千米？
<gadget id="calculator">30 * 9</gadget>
<output>270</output>

<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<gadget id="calculator">270 / 3</gadget>
<output>90</output>

<gadget id="calculator">90 * 12</gadget>
<output>1_080</output>

<result>1_080</result>