LCM( 28, 56, 98 ) = 392
Step 1: Write down factorisation of each number:
28 = 2 · 2 · 7
56 = 2 · 2 · 2 · 7
98 = 2 · 7 · 7
Step 2 : Match primes vertically:
28 | = | 2 | · | 2 | · | 7 | ||||
56 | = | 2 | · | 2 | · | 2 | · | 7 | ||
98 | = | 2 | · | 7 | · | 7 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
28 | = | 2 | · | 2 | · | 7 | ||||||
56 | = | 2 | · | 2 | · | 2 | · | 7 | ||||
98 | = | 2 | · | 7 | · | 7 | ||||||
LCM | = | 2 | · | 2 | · | 2 | · | 7 | · | 7 | = | 392 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.