1. The problem is to solve the equation $\frac{c}{15} = 3$ for $c$. 2. The formula used here is to isolate $c$ by multiplying both sides of the equation by 15 to cancel the denominator. 3. Multiply both sides by 15: $$\cancel{15} \times \frac{c}{\cancel{15}} = 3 \times 15$$ 4. Simplify the left side by canceling 15 in numerator and denominator: $$c = 45$$ 5. Therefore, the solution to the equation $\frac{c}{15} = 3$ is $c = 45$. This means that when $c$ is 45, dividing it by 15 gives 3, which satisfies the original equation.