问题217: 如圖所示,四個隐輪相互連接。第一個有30個齒,第二個有15個,第三個有60個,第四個有10個。第一個齒輪每轉一整圈,最後一個齒輪轉多少圈?

如圖所示,四個隐輪相互連接。第一個有30個齒,第二個有15個,第三個有60個,第
四個有10個。第一個齒輪每轉一整圈,最後一個齒輪轉多少圈?
Four cogs are connected to each other as shown in the picture. The first has 30 teeth, the second 15 , the third 60 and the fourth 10 . How many turns will the last cog make for each full turn of the first cog ?