A rides a bicycle to catch up with B who is walking in front. B's speed is 60 meters per minute, and A's speed is 150 meters per minute. If A catches up with B 8 minutes after starting, then how many minutes before B starts before A?
甲骑自行车追赶前面步行的乙，乙的速度是每分钟60米，甲的速度是每分钟150米．甲出发8分钟追上了乙，那么乙比甲早出发多少分钟．
<gadget id="calculator">150 - 60</gadget>
<output>90</output>

<gadget id="calculator">8 / 60</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">90 * (2/15)</gadget>
<output>12</output>

<result>12</result>