LCM( 80, 85, 90 ) = 12240
Step 1 : Write the given numbers in a horizontal line.
80 | 85 | 90 |
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 | 80 | 85 | 90 |
40 | 85 | 45 |
Step 3 : Continue dividing by prime numbers till we get 1 in all columns.
2 | 80 | 85 | 90 |
2 | 40 | 85 | 45 |
2 | 20 | 85 | 45 |
2 | 10 | 85 | 45 |
3 | 5 | 85 | 45 |
3 | 5 | 85 | 15 |
5 | 5 | 85 | 5 |
17 | 1 | 17 | 1 |
1 | 1 | 1 |
Step 4 : Multiply numbers in first column to get LCM.
LCM( 80, 85, 90 ) = 2 · 2 · 2 · 2 · 3 · 3 · 5 · 17 = 12240 .
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.