Least Common Multiple  of 9 and 15 is 45

How to find the Least Common Multiple of 9 and 15?

On this page below, we'll use the Prime Factorisation, and the List of Multiples method to find out the LCM of 9 and 15.

Follow the steps below, and let's calculate the LCM of 9 and 15.


Method 1 - Prime factorization

Step 1: Create a list of all the prime factors of the numbers 9 and 15:

Prime factors of 9

The prime factors of 9 are 3 and 3. Prime factorization of 9 in exponential form is:

9 = 32

Prime factors of 15

The prime factors of 15 are 3 and 5. Prime factorization of 15 in exponential form is:

15 = 31x51


Step 2: Identify the highest power of each prime number from the above boxes:

32, 51


Step 3: Multiply these values together:

32x51=45


Step 4: The result:

As seen on the calculation above, we have now obtained the LCM of 9 and 15.

The Least Common Multiple of 9 and 15 is 45.


Method 2 - List of Multiples

Find and list multiples of each number until the first common multiple is found. This is the lowest common multiple.


Multiples of 9:

9, 18, 27, 36, 45, 54, 63, 72

Multiples of 15:

15, 30, 45, 60, 75, 90


Therefore,

LCM(9, 15) = 45