LCM( 13, 29, 21 ) = 7917
Step 1 : Write the given numbers in a horizontal line.
13 | 29 | 21 |
Step 2 : Divide the given numbers by smallest prime number. In this example we can divide by 3.
(if any number is not divisible by 3, write it down unchanged)
3 | 13 | 29 | 21 |
13 | 29 | 7 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
3 | 13 | 29 | 21 |
7 | 13 | 29 | 7 |
13 | 13 | 29 | 1 |
29 | 1 | 29 | 1 |
1 | 1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 13, 29, 21 ) = 3 · 7 · 13 · 29 = 7917 .
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.