One person is riding a bicycle and one person is walking on the same road, driving in the same direction. The speed of the driver is four times that of the pedestrian. Every eight minutes, a bus passes the pedestrian, and there is a bus every twelve minutes. Exceeding the cyclist, if the departure time of the bus departure station remains the same, how many minutes does it take to send a bus?
一人骑自行车和一人步行在同一条公路上，同方向行驶，驶车人的速度是步行人的4倍，每隔八分钟，有一辆公共汽车超过步行人，每隔十二分钟有一辆公共汽车超过骑车人，若公交车始发站发车时间不变，那么隔多少分钟发一辆车？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

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

<gadget id="calculator">(1/8) - (1/12)</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">(1/24) / 3</gadget>
<output>1/72 = around 0.013889</output>

<gadget id="calculator">(1/72) + (1/8)</gadget>
<output>5/36 = around 0.138889</output>

<gadget id="calculator">1 / (5/36)</gadget>
<output>36/5 = around 7.2</output>

<result>36/5 = around 7.2</result>