and B go back and forth between A and B, which are 1000 meters apart. A starts from point A first, and B also starts from point A 6 minutes later, and catches up with A at point C, which is 600 meters away from point A. After B arrives at B, he immediately returns to A at the same speed. After A rests for 1 minute at B, he speeds up and returns to A, and catches up with B at C. Question: How many minutes earlier does A return to A than B?
甲、乙往返于相距1000米的A，B两地．甲先从A地出发，6分钟后乙也从A地出发，并在距A地600米的C地追上甲．乙到B地后立即原速向A地返回，甲到B地休息1分钟后加快速度向A地返回，并在C地追上乙．问：甲比乙提前多少分钟回到A地？
<gadget id="calculator">15 / 2</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>