Question

A photo 5 inches wide and 8 inches long is enlarged.

How wide is the new photo if it is (1)12 inches; (2)20 inches; (3)10 inches long?

Answer 1

1. Let original dimensions be W1 and L1
New dimensions designated as W2 and L2

Equation: W2/W1=L2/L1 ..... A equal proportion

Thus...

(1) W2/5=12/8. (2) W2/5=20/8
W2= 5(12/8) W2=5(20/8)
W2=5(1.5) W2=5(2.5)
W2=7.5" W2=12.5"

(3) W2/5=10/8
W2=5(10/8)
W2=5(1.25)
W2=6.25"

Answer 2

1. 7.5 inches
2. 12.5 inches
3. 6.25 inches