LCM( 65, 80, 120 ) = 3120
Step 1 : Write the given numbers in a horizontal line.
| 65 | 80 | 120 |
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 | 65 | 80 | 120 |
| 65 | 40 | 60 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
| 2 | 65 | 80 | 120 |
| 2 | 65 | 40 | 60 |
| 2 | 65 | 20 | 30 |
| 2 | 65 | 10 | 15 |
| 3 | 65 | 5 | 15 |
| 5 | 65 | 5 | 5 |
| 13 | 13 | 1 | 1 |
| 1 | 1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 65, 80, 120 ) = 2 · 2 · 2 · 2 · 3 · 5 · 13 = 3120 .
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.