If an eco-lightbulb is sold for $x, there is a loss of 15% based on the cost of materials required to produce it. If the same bulb is sold for $y, there is a profit of 15% based on the cost. What is the ratio of x to y?
Let's write x and y each in terms of the cost, C, and then compare them.
We know x = .85C and y = 1.15C.
So x/y = .85C/1.15C = .85/1.15 = 17/23.
The ratio of x to y is 17 to 23.