LCM( 10, 18, 45 ) = 90
Step 1: Write down factorisation of each number:
10 = 2 · 5
18 = 2 · 3 · 3
45 = 3 · 3 · 5
Step 2 : Match primes vertically:
10 | = | 2 | · | 5 | ||||
18 | = | 2 | · | 3 | · | 3 | ||
45 | = | 3 | · | 3 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
10 | = | 2 | · | 5 | ||||||
18 | = | 2 | · | 3 | · | 3 | ||||
45 | = | 3 | · | 3 | · | 5 | ||||
LCM | = | 2 | · | 3 | · | 3 | · | 5 | = | 90 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.