How to find the Least Common Multiple of 9 and 20?
On this page below, we'll use the Prime Factorisation, and the List of Multiples method to find out the LCM of 9 and 20.
Follow the steps below, and let's calculate the LCM of 9 and 20.
Method 1 - Prime factorization
Step 1: Create a list of all the prime factors of the numbers 9 and 20:
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 20
The prime factors of 20 are 2, 2 and 5. Prime factorization of 20 in exponential form is:
20 = 22x51
Step 2: Identify the highest power of each prime number from the above boxes:
32, 22, 51
Step 3: Multiply these values together:
32x22x51=180
Step 4: The result:
As seen on the calculation above, we have now obtained the LCM of 9 and 20.
The Least Common Multiple of 9 and 20 is 180.
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, 81, 90, 99, 108, 117, 126, 135, 144, 153, 162, 171, 180, 189, 198, 207
Multiples of 20:
20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240
Therefore,
LCM(9, 20) = 180