LCM for 9 and 20

The first method to find LCM for numbers 9 and 20 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 9 and 20 is 1, so

LCM = (9 × 20) ÷ 1

LCM = 180 ÷ 1

LCM = 180

The second method to find LCM for numbers 9 and 20 is to list out the common multiples for both nubmers and pick the first which matching:

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

Multiples of 20: 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220

So the LCM for 9 and 20 is 180

Another method to find LCM for numbers 9 and 20 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors: