LCM( 10, 55, 90 ) = 990
Step 1: Write down factorisation of each number:
10 = 2 · 5
55 = 5 · 11
90 = 2 · 3 · 3 · 5
Step 2 : Match primes vertically:
10 | = | 2 | · | 5 | ||||||
55 | = | 5 | · | 11 | ||||||
90 | = | 2 | · | 3 | · | 3 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
10 | = | 2 | · | 5 | ||||||||
55 | = | 5 | · | 11 | ||||||||
90 | = | 2 | · | 3 | · | 3 | · | 5 | ||||
LCM | = | 2 | · | 3 | · | 3 | · | 5 | · | 11 | = | 990 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.