LCM( 120, 225, 210 ) = 12600
Step 1 : Write the given numbers in a horizontal line.
120 | 225 | 210 |
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 | 120 | 225 | 210 |
60 | 225 | 105 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
2 | 120 | 225 | 210 |
2 | 60 | 225 | 105 |
2 | 30 | 225 | 105 |
3 | 15 | 225 | 105 |
3 | 5 | 75 | 35 |
5 | 5 | 25 | 35 |
5 | 1 | 5 | 7 |
7 | 1 | 1 | 7 |
1 | 1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 120, 225, 210 ) = 2 · 2 · 2 · 3 · 3 · 5 · 5 · 7 = 12600 .
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.