LCM( 13, 36, 40 ) = 4680
Step 1: Write down factorisation of each number:
13 = 13
36 = 2 · 2 · 3 · 3
40 = 2 · 2 · 2 · 5
Step 2 : Match primes vertically:
13 | = | 13 | ||||||||||||
36 | = | 2 | · | 2 | · | 3 | · | 3 | ||||||
40 | = | 2 | · | 2 | · | 2 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
13 | = | 13 | ||||||||||||||
36 | = | 2 | · | 2 | · | 3 | · | 3 | ||||||||
40 | = | 2 | · | 2 | · | 2 | · | 5 | ||||||||
LCM | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | · | 5 | · | 13 | = | 4680 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.