LCM( 15, 20, 30 ) = 60
Step 1 : Place the numbers inside division bar:
15 | 20 | 30 |
Step 2 : Find a prime number which can divide at least two of your numbers.
In this example we can divide by 3. If any number is not divisible by 3 write it down unchanged.
3 | 15 | 20 | 30 |
5 | 20 | 10 |
Step 3 : Repeat Step 2 until you can no longer divide.
3 | 15 | 20 | 30 |
5 | 5 | 20 | 10 |
1 | 4 | 2 |
3 | 15 | 20 | 30 |
5 | 5 | 20 | 10 |
2 | 1 | 4 | 2 |
1 | 2 | 1 |
Since there are no primes that divides at least two of given numbers, we conclude that the LCM is a product of starting numbers.
LCM = 15 · 20 · 30 = 60
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.