A young mountaineering team took 20 minutes from the foot of the mountain to the top at a speed of 40 meters per minute, and immediately returned from the original road and took 12 minutes to reach the original place. Ask the mountaineering team what is the average speed per minute during the entire process of going up and down the mountain? How much rice.
一少年登山队以每分钟40米的速度，从山脚到山顶用了20分钟，立即从原路返回用了12分钟到达了原地，问登山小队整个上山和下山过程中平均每分钟的速度是多少米．
<result>650</result>