Two people, A and B, race around a circular square with a circumference of 1200 meters. It is known that A walks 80 meters per minute, and B's speed is twice that of A. Now A is 240 meters behind B, how many minutes does it take for B to catch up with A?
甲、乙两人绕周长1200米的环形广场竞走，已知甲每分钟走80米，乙的速度是甲的2倍．现在甲在乙后面240米，乙追上甲需要多少分钟？
<gadget id="calculator">1_200 - 240</gadget>
<output>960</output>

<gadget id="calculator">80 * 2</gadget>
<output>160</output>

<gadget id="calculator">160 - 80</gadget>
<output>80</output>

<gadget id="calculator">960 / 80</gadget>
<output>12</output>

<result>12</result>