How to find the Least Common Multiple of 20 and 31?
On this page below, we'll use the Prime Factorisation, and the List of Multiples method to find out the LCM of 20 and 31.
Follow the steps below, and let's calculate the LCM of 20 and 31.
Method 1 - Prime factorization
Step 1: Create a list of all the prime factors of the numbers 20 and 31:
Prime factors of 20
The prime factors of 20 are 2, 2 and 5. Prime factorization of 20 in exponential form is:
20 = 22x51
Prime factors of 31
The prime factors of 31 are 31. Prime factorization of 31 in exponential form is:
31 = 311
Step 2: Identify the highest power of each prime number from the above boxes:
22, 51, 311
Step 3: Multiply these values together:
22x51x311=620
Step 4: The result:
As seen on the calculation above, we have now obtained the LCM of 20 and 31.
The Least Common Multiple of 20 and 31 is 620.
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 20:
20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540, 560, 580, 600, 620, 640, 660, 680
Multiples of 31:
31, 62, 93, 124, 155, 186, 217, 248, 279, 310, 341, 372, 403, 434, 465, 496, 527, 558, 589, 620, 651, 682, 713
Therefore,
LCM(20, 31) = 620