LCM( 384, 320, 420 ) = 13440
Step 1 : Write the given numbers in a horizontal line.
384 | 320 | 420 |
Step 2 : Divide the given numbers by smallest prime number. In this example we can divide by 2.
(if any number is not divisible by 2, write it down unchanged)
2 | 384 | 320 | 420 |
192 | 160 | 210 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
2 | 384 | 320 | 420 |
2 | 192 | 160 | 210 |
2 | 96 | 80 | 105 |
2 | 48 | 40 | 105 |
2 | 24 | 20 | 105 |
2 | 12 | 10 | 105 |
2 | 6 | 5 | 105 |
3 | 3 | 5 | 105 |
5 | 1 | 5 | 35 |
7 | 1 | 1 | 7 |
1 | 1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 384, 320, 420 ) = 2 · 2 · 2 · 2 · 2 · 2 · 2 · 3 · 5 · 7 = 13440 .
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.