LCM( 49, 80 ) = 3920
Step 1: Write down factorisation of each number:
49 = 7 · 7
80 = 2 · 2 · 2 · 2 · 5
Step 2 : Match primes vertically:
49 | = | 7 | · | 7 | ||||||||||
80 | = | 2 | · | 2 | · | 2 | · | 2 | · | 5 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
49 | = | 7 | · | 7 | ||||||||||||
80 | = | 2 | · | 2 | · | 2 | · | 2 | · | 5 | ||||||
LCM | = | 2 | · | 2 | · | 2 | · | 2 | · | 5 | · | 7 | · | 7 | = | 3920 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.