LCM( 5, 9, 15 ) = 45
Step 1: Write down factorisation of each number:
5 = 5
9 = 3 · 3
15 = 3 · 5
Step 2 : Match primes vertically:
5 | = | 5 | ||||
9 | = | 3 | · | 3 | ||
15 | = | 3 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
5 | = | 5 | ||||||
9 | = | 3 | · | 3 | ||||
15 | = | 3 | · | 5 | ||||
LCM | = | 3 | · | 3 | · | 5 | = | 45 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.