LCM( 312, 18, 39 ) = 936
Step 1: Write down factorisation of each number:
312 = 2 · 2 · 2 · 3 · 13
18 = 2 · 3 · 3
39 = 3 · 13
Step 2 : Match primes vertically:
312 | = | 2 | · | 2 | · | 2 | · | 3 | · | 13 | ||
18 | = | 2 | · | 3 | · | 3 | ||||||
39 | = | 3 | · | 13 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
312 | = | 2 | · | 2 | · | 2 | · | 3 | · | 13 | ||||
18 | = | 2 | · | 3 | · | 3 | ||||||||
39 | = | 3 | · | 13 | ||||||||||
LCM | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | · | 13 | = | 936 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.