# What is the LCM of 40 and 70?

To find the LCM of 40 and 70, we need the least number which is exactly divisible by both 40 and 70.

## Answer: LCM of 40 and 70 is 280

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

## Explanation:

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

### Method 1: LCM of 40 and 70 by Listing Method

List the first few multiples of 40 and 70 and identify the common multiples.

The least among the common multiples is the LCM of 40 and 70

Multiples of 40: 40, 80, 120, 160, 200, 240, __ 280__, 320

Multiples of 70: 70, 140, 210, __ 280__, 350

So, by this method, LCM of 40 and 70 is 280.

### Method 2: LCM of 40 and 70 by Formula

The formula of LCM is LCM (a, b) = (a × b) / GCF (a, b)

The Greatest Common Factor (GCF) of (40, 70) = 10

Therefore,

LCM of 40 and 70 = (40 × 70) / 10

= 2800 / 10

= 280

LCM (40, 70) = 280

Observe that the solution to our question LCM of 40 and 70 is the same in both methods.