Two children walk on the same ground at the same time and in the same direction at a speed of 60 meters per minute. After walking for 15 minutes, A returns to the starting point to pick up things while B continues to move forward. It took 5 minutes for A to fetch something, and then A chases B on a bicycle at 360 m/min. How many minutes does it take for A to catch up with B?
两个小朋友以60米每分的速度同时同地同向步行．走15分钟后甲返回出发地取东西而乙继续前进．甲取东西用了5分钟，然后甲骑自行车以360米/分追乙，甲需要几分钟能追上乙？
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<gadget id="calculator">30 + 5</gadget>
<output>35</output>

<gadget id="calculator">360 - 60</gadget>
<output>300</output>

<gadget id="calculator">35 / 300</gadget>
<output>7/60 = around 0.116667</output>

<gadget id="calculator">60 * (7/60)</gadget>
<output>7</output>

<result>7</result>