LCM( 48, 56, 70 ) = 1680
Step 1: Write down factorisation of each number:
48 = 2 · 2 · 2 · 2 · 3
56 = 2 · 2 · 2 · 7
70 = 2 · 5 · 7
Step 2 : Match primes vertically:
48 | = | 2 | · | 2 | · | 2 | · | 2 | · | 3 | ||||
56 | = | 2 | · | 2 | · | 2 | · | 7 | ||||||
70 | = | 2 | · | 5 | · | 7 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
48 | = | 2 | · | 2 | · | 2 | · | 2 | · | 3 | ||||||
56 | = | 2 | · | 2 | · | 2 | · | 7 | ||||||||
70 | = | 2 | · | 5 | · | 7 | ||||||||||
LCM | = | 2 | · | 2 | · | 2 | · | 2 | · | 3 | · | 5 | · | 7 | = | 1680 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.