LCM( 21, 36, 66 ) = 2772
Step 1: Write down factorisation of each number:
21 = 3 · 7
36 = 2 · 2 · 3 · 3
66 = 2 · 3 · 11
Step 2 : Match primes vertically:
21 | = | 3 | · | 7 | ||||||||
36 | = | 2 | · | 2 | · | 3 | · | 3 | ||||
66 | = | 2 | · | 3 | · | 11 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
21 | = | 3 | · | 7 | ||||||||||
36 | = | 2 | · | 2 | · | 3 | · | 3 | ||||||
66 | = | 2 | · | 3 | · | 11 | ||||||||
LCM | = | 2 | · | 2 | · | 3 | · | 3 | · | 7 | · | 11 | = | 2772 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.