Two small electric toys, A and B, start at the same time on a circular track and run in the opposite direction. It is known that the speed of A is 40cm per second, and the speed of B is 60cm per second. In 2 minutes, they meet 40 times, then What is the length of the track in cm.
甲、乙两个小电动玩具在一圆形轨道上同时出发，反向行驶，已知甲的速度是每秒40cm，乙的速度是每秒60cm，在2分钟内，它们相遇40次，则轨道长为多少cm．
<gadget id="calculator">40 + 60</gadget>
<output>100</output>

<gadget id="calculator">2 / 40</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">100 * 60 * (1/20)</gadget>
<output>300</output>

<result>300</result>