LCM( 54, 63, 90 ) = 1890
Step 1: Write down factorisation of each number:
54 = 2 · 3 · 3 · 3
63 = 3 · 3 · 7
90 = 2 · 3 · 3 · 5
Step 2 : Match primes vertically:
54 | = | 2 | · | 3 | · | 3 | · | 3 | ||||
63 | = | 3 | · | 3 | · | 7 | ||||||
90 | = | 2 | · | 3 | · | 3 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
54 | = | 2 | · | 3 | · | 3 | · | 3 | ||||||
63 | = | 3 | · | 3 | · | 7 | ||||||||
90 | = | 2 | · | 3 | · | 3 | · | 5 | ||||||
LCM | = | 2 | · | 3 | · | 3 | · | 3 | · | 5 | · | 7 | = | 1890 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.