Question

A photo is reduced with a scale factor of 1 to 3. If the photo is now 4 inches wide, how wide was the original photo? Show the math.

Answer 1

12 inches, I mean, you just have to take the size and multiply by 3

Answer 2

12 inches wide.

Explanation:

It is reduced to a 1:3 factor. where 1 is the new length and 3 is the old length. We can write a proportion
`1:3=4:x`. Now, if four numbers are in a proportion we can cross-multiply and we get
`1x=3\cdot 4 \rightarrow x = 12`.