LCM( 10, 2 ) = 10
The formula for finding LCM is
$$ \text{LCM} (a, b) = \frac{ a \cdot b }{ \text{GCD}(a,b)} $$In this example we have: a = 10, b = 2 and GCD(10, 2) = 2.
$$ \text{LCM} (10, 2) = \frac{ 10 \cdot 2 }{ \text{GCD}(10,2)} = \frac{ 20 }{ 2 } = 10 $$