Question

a scale model of a bridge uses 1 inch : 30 feet. if the bridge is 90 feet long, how long is it in the model? ? inches

Explanation:

Step1: Set up proportion

Let $x$ be the length of the model in inches. The proportion is $\frac{1}{30}=\frac{x}{90}$.

Step2: Cross - multiply

$30x = 1\times90$.

Step3: Solve for $x$

$x=\frac{90}{30}=3$.

Answer:

3