The distance between Xiaogang and Xiaohong is 840 meters. Xiaogang is going to deliver books to Xiaohong. To save time, the two leave home at the same time. Xiaogang walks an average of 60 meters per minute, and Xiaohong walks an average of 40 meters per minute. How many minutes later did the two meet?
小刚和小红两家相距840米，小刚要去给小红送书，为节省时间，两人同时从家出发．小刚平均每分钟走60米，小红平均每分钟走40米．几分钟后两人相遇？
<gadget id="calculator">60 + 40</gadget>
<output>100</output>

<gadget id="calculator">840 / 100</gadget>
<output>42/5 = around 8.4</output>

<result>42/5 = around 8.4</result>