Question

Problem: A scale model of an airplane has a scale of inch = 2 feet the actual length of the plane is 40 feet long. How long is the scale model?

Answer 1

The scale is:

`(1)/(4)inch=2\text{ fe}et`

This means that every 1/4 inch in the scale model represents 2 feet of the real plane.

The real length of the plane is:

`40\text{ ft}`

To solve this problem is useful to take the scale:

`(1)/(4)inch=2\text{ fe}et`

And find how many inches represent just 1 foot. We can find this by dividing both sides by 2:

`(1)/(8)\text{inch}=1\text{feet}`

Now that we know that 1 foot represents 1/8 inches, the last step is to multiply 40 feet by 1/8 and we will find the length of the plane in the scale model:

`40*(1)/(8)\text{inch}=(40)/(8)\text{inch}=5\text{inch}`

Answer: the length in the scale model is 5 inches.