LCM( 105, 90, 126 ) = 630
Step 1: Write down factorisation of each number:
105 = 3 · 5 · 7
90 = 2 · 3 · 3 · 5
126 = 2 · 3 · 3 · 7
Step 2 : Match primes vertically:
105 | = | 3 | · | 5 | · | 7 | ||||
90 | = | 2 | · | 3 | · | 3 | · | 5 | ||
126 | = | 2 | · | 3 | · | 3 | · | 7 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
105 | = | 3 | · | 5 | · | 7 | ||||||
90 | = | 2 | · | 3 | · | 3 | · | 5 | ||||
126 | = | 2 | · | 3 | · | 3 | · | 7 | ||||
LCM | = | 2 | · | 3 | · | 3 | · | 5 | · | 7 | = | 630 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.