The two brothers set off from home to school at the same time. The elder brother walked 80 meters per minute, and the younger brother walked 60 meters per minute. After 10 minutes of departure, the elder brother returned home to pick up the stationery, and then immediately rode a bicycle at a speed of 310 meters per minute to catch up with the younger brother. How many minutes did it take for the older brother to catch up with the younger brother?
兄弟二人同时从家出发去学校，哥哥每分钟走80米，弟弟每分钟走60米．出发10分钟后，哥哥返回家中取文具，然后立即骑车以每分钟310米的速度去追弟弟，哥哥骑车过多少分钟追上弟弟．
<gadget id="calculator">60 * 10 * 2</gadget>
<output>1_200</output>

<gadget id="calculator">310 - 60</gadget>
<output>250</output>

<gadget id="calculator">1_200 / 250</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>