# What is the LCM of 28 and 30?

To find the LCM of 28 and 30, we need the least number which is exactly divisible by both 28 and 30.

## Answer: LCM of 28 and 30 is 420

The Least Common Multiple (LCM) of two numbers a and b is the smallest number that is divisible by a and b.

## Explanation:

We can find the LCM of the numbers in the following two ways.

### Method 1: LCM of 28 and 30 by Listing Method

We will list the first few multiples of 28 and 30 and determine the common multiples.

The least among the common multiples is the LCM of 28 and 30.

So, LCM of 28 and 30 = 420

### Method 2: LCM of 28 and 30 by Formula

The formula of LCM is

LCM (a,b) = (a × b) / GCF (a,b)

The Greatest Common Factor (GCF) of 28 and 30 is 2. So, GCF (28, 30) = 2

So, the LCM of 28 and 30 by using the formula,

LCM (28, 30) = (28 × 30) / 2

= 840 / 2

= 420

LCM of 28 and 30 = 420

Observe that the solution to our question LCM of 28 and 30 is the same in both methods.