LCM( 3, 12, 7, 5 ) = 420
Step 1 : Write the given numbers in a horizontal line.
3 | 12 | 7 | 5 |
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 | 3 | 12 | 7 | 5 |
3 | 6 | 7 | 5 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
2 | 3 | 12 | 7 | 5 |
2 | 3 | 6 | 7 | 5 |
3 | 3 | 3 | 7 | 5 |
5 | 1 | 1 | 7 | 5 |
7 | 1 | 1 | 7 | 1 |
1 | 1 | 1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 3, 12, 7, 5 ) = 2 · 2 · 3 · 5 · 7 = 420 .