To solve the equation \( 12 = 8b \), you can isolate \( b \) by dividing both sides of the equation by 8:
\[ b = \frac{12}{8} \]
This simplifies to:
\[ b = \frac{3}{2} \quad \text{or} \quad b = 1.5 \]
So, the solution is \( b = \frac{3}{2} \) or \( b = 1.5 \).