我想問10,50,24既L.C.M係咩?(10點!)

我想問10,50,24既L.C.M係咩?
又有咩方法去知道?
sol
2 |10, 50, 24
-------------------
5 | 5, 25, 12
------------------
1, 5, 12

2*5*1*5*12=600

我們列舉法或短除法來找10,50,24的L.C.M

列舉法:

10的倍數有:10,20,30,40,50,60,70,80,90,100,110,120,130,140,150,160,170,180,190,200,210,220,230,240,250,260,270,280,290,300,310,320,330,340,350,360,370,380,390,400,410,420,430,440,450,460,470,480,490,500,510,520,530,540,550,560,570,580,590,600,610......

50的倍數有:50,100,150,200,250,300,350,400,450,500,550,600,650......

24的倍數有:24,48,72,96,120,144,168,192,216,240,264,288,312,336,360,384,408,432,456,480,504,528,552,576,600......

你會發覺它們有些數字會在10的倍數,50的倍數,24的倍數重複出現,最小的一個就是它們的L.C.M,所以10,50,24的L.C.M就是600

以上的方法需要很久,所以我介紹一種又省時又快捷的短除法

短除法:

2| 10 50 24
..------------
5| 05 25 12
..------------
__01 05 12

如果你用短除法,要謹記下列規則:

1)一有二個或以上的數字可以被一個1以上的整數除盡後是整數的也要除

2)除不盡的就照寫(上面例子)

3)找最左邊和最下面的數字相乘便是它們的L.C.M(上面的例子的L.C.M2x5x1x5x12=600)

So,10,50,24的L.C.M是600

10 = 2 x 5
50 = 2 x 5 x 5
24 = 2 x 2 x 2 x 3
so their LCM is 2 x 2 x 2 x 5 x 5 x 3 = 600 ( by taking the greatest number of 2 , 5 and 3 among 10, 50 and 24)