Question
Find Least Common Multiple of 3, 7 and 9 using prime factorisation method.
Answer
LCM( 3, 7, 9 ) = 63
Explanation
Step 1: Write down factorisation of each number:
3 = 3
7 = 7
9 = 3 · 3
Step 2 : Match primes vertically:
| 3 | = | 3 | ||||
| 7 | = | 7 | ||||
| 9 | = | 3 | · | 3 |
Step 3 : Bring down numbers in each column and multiply to get LCM:
| 3 | = | 3 | ||||||
| 7 | = | 7 | ||||||
| 9 | = | 3 | · | 3 | ||||
| LCM | = | 3 | · | 3 | · | 7 | = | 63 |
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.
This page was created using
LCM Calculator