LCM( 9800, 420, 2520 ) = 88200
Step 1: Write down factorisation of each number:
9800 = 2 · 2 · 2 · 5 · 5 · 7 · 7
420 = 2 · 2 · 3 · 5 · 7
2520 = 2 · 2 · 2 · 3 · 3 · 5 · 7
Step 2 : Match primes vertically:
9800 | = | 2 | · | 2 | · | 2 | · | 5 | · | 5 | · | 7 | · | 7 | ||||
420 | = | 2 | · | 2 | · | 3 | · | 5 | · | 7 | ||||||||
2520 | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | · | 5 | · | 7 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
9800 | = | 2 | · | 2 | · | 2 | · | 5 | · | 5 | · | 7 | · | 7 | ||||||
420 | = | 2 | · | 2 | · | 3 | · | 5 | · | 7 | ||||||||||
2520 | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | · | 5 | · | 7 | ||||||
LCM | = | 2 | · | 2 | · | 2 | · | 3 | · | 3 | · | 5 | · | 5 | · | 7 | · | 7 | = | 88200 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.