Question

The length of a model plane is `10 1/2` inches. The scale of the model is `1:72`. What is the length of the real plane?

Answer 1

63 feet

Explanation:

In order to make this problem easier to work with, let's change `10 1/2` to a decimal. Since `1/2 = 0.5` we can change the length of the model to to `10.5` inches.

The scale of the model to the plane is `1:75` or (using words)

one inch on the model : 72 inches on the real plane

Well, this model isn't just one inch, it's `10.5` inches. So we will multiply `10.5` by `72` to find out how long the actual plane is.

`10.5 xx 72 = 756` inches

As an extra step, you may want to find out how many feet `756` is, because large numbers typically aren't measured in inches. Since there are 12 inches in 1 foot, we will divide `756/12` to find out how many feet it equals.

`756/12 = 63` feet