LCM( 54, 56, 84 ) = 1512
Step 1: Write down factorisation of each number:
54 = 2 · 3 · 3 · 3
56 = 2 · 2 · 2 · 7
84 = 2 · 2 · 3 · 7
Step 2 : Match primes vertically:
54 | = | 2 | · | 3 | · | 3 | · | 3 | ||||||
56 | = | 2 | · | 2 | · | 2 | · | 7 | ||||||
84 | = | 2 | · | 2 | · | 3 | · | 7 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
54 | = | 2 | · | 3 | · | 3 | · | 3 | ||||||||
56 | = | 2 | · | 2 | · | 2 | · | 7 | ||||||||
84 | = | 2 | · | 2 | · | 3 | · | 7 | ||||||||
LCM | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | · | 3 | · | 7 | = | 1512 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.