LCM( 28, 36 ) = 252
The formula for finding LCM is
$$ \text{LCM} (a, b) = \frac{ a \cdot b }{ \text{GCD}(a,b)} $$In this example we have: a = 28, b = 36 and GCD(28, 36) = 4.
$$ \text{LCM} (28, 36) = \frac{ 28 \cdot 36 }{ \text{GCD}(28,36)} = \frac{ 1008 }{ 4 } = 252 $$