The first thing you should do in this case is to know how much paper you need to print for the 17 copies.
We have then:
(17) * (130) = 2210
Then, you must calculate the number of reams you need:
n = (2210) / (500) = 4.42
You need 4 full reams and 42% of a fifth ream. So, the cost will be
C = (4.42) * (3.44) = 15.2048 $
The unit cost of each paper is:
Cu = (15.2048) / (2210) = 0.00688 $
answer
the paper is going to cost 0.00688 $ for those reports
I think it might be f^-1 (x) = x/2 - 3/2
I hope this helps!
Because the ratio for both candles is 20/60 or 1/3 then take the number of ounces the candle has and divide by 1/3. In expression: 9 / 1/3 => 9 * 3 = 18