一台拖拉机,后轮直径是前轮直径的3倍,后轮滚动40圈,前轮滚动()
问题描述：
一台拖拉机,后轮直径是前轮直径的3倍,后轮滚动40圈,前轮滚动()
答
3*40=120
一台拖拉机,后轮直径是前轮直径的3倍,后轮滚动40圈,前轮滚动(120圈)