# What is the LCM (Lowest Common Multiple) of 16 and 20?

Oct 12, 2017

$L C M = 2 \cdot 2 \cdot 3 \cdot 5 =$60

#### Explanation:

Let us first factorise both the terms $20 \mathmr{and} 15.$

$20 = 2 \cdot 2 \cdot \textcolor{red}{5}$
$15 = 3 \cdot \textcolor{red}{5}$

5 has repeated in both the terms and hence included once in LCM.

$L C M \left(15 , 20\right) = 2 \cdot 2 \cdot 5 \cdot 3 =$60

Oct 12, 2017

$\lcm \left(16 , 20\right) = 60$

#### Explanation:

Another way is to simply list the multiples of the numbers and pick out the common ones

"15:{15,30,45color(red)(,60),75,90,105,color(red)(120),.....}

"20:{20,40color(red)(,60),80,100,color(red)(120),...}

common multiples:$\text{ } \left\{60 , 120 , . .\right\}$

$\lcm \left(16 , 20\right) = 60$