LCM( 18, 29, 21 ) = 3654
Step 1 : Write the given numbers in a horizontal line.
18 | 29 | 21 |
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 | 18 | 29 | 21 |
9 | 29 | 21 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
2 | 18 | 29 | 21 |
3 | 9 | 29 | 21 |
3 | 3 | 29 | 7 |
7 | 1 | 29 | 7 |
29 | 1 | 29 | 1 |
1 | 1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 18, 29, 21 ) = 2 · 3 · 3 · 7 · 29 = 3654 .
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.