Scale question

Question

Two points on a highway are exactly one mile apart. If the corresponding photo distance is 4.2 inches what is the scale of the photograph?

 

 

Answer 1

Scale is usually written in the form 1 inch = 3 miles. Here the "=" sign does not mean the same as 2 + 4= 6.

It means 1 inch on the picture = 3 miles on the earth. So:

 

4.2 in = 1 mi               divide both sides by 4.2

1 in ≈ 0.238 mi

 

This could be calculated in feet.

0.238 mi ≈ 1256.64 ft

1 in ≈ 1256.64 ft