Question

A model of the Cape Hatteras Lighthouse uses a scale of 8 inches 30 feet. If the actual lighthouse is 210 feet tall, how tall is the model?

Answer 1

The scale model is `56 " inches"` tall.

Explanation:

Strategy: Use the fact that `8` inches = `30` feet as a conversion factor to scale `210` foot tower to scale model size.

Step 1. Conversion factor.

`8 " inches"=30" feet"` can be turned into a conversion factor in one of two ways:

`(8" inches")/(30" feet")` or `(30" feet")/(8" inches")`

Step 2. Scale the `210` feet by the conversion factor which cancels feet and keeps inches.

`210cancel(" feet")xx(8" inches")/(30cancel(" feet"))=56" inches"`