An ant covers a distance of 90 meters in 3 hours ,The average speed of the ant in decimeters per
问题描述：
An ant covers a distance of 90 meters in 3 hours ,The average speed of the ant in decimeters per
答
一只蚂蚁3个小时走了90米,蚂蚁平均速度是每分钟多少分米？
（1米=10分米）
答
一只蚂蚁走了3个小时,一共90米的距离,
这只蚂蚁的速度是平均每分钟多少分米?
900/(3*60) =5