Answer:
9.09 ounces
Explanation:
The added water can be calculated by writing an equation for the amount of iodine in the diluted solution.
Setup
Let x represent the number of ounces of water added to the 60% solution. The total amount of iodine in the mixture is ...
0.60(100) +0(x) = 0.55(100+x) . . . . . ounces of iodine in the mix
Solution
Simplify the equation:
60 = 55 +0.55x
5 = 0.55x . . . . . . . subtract 55
x = 5/0.55 ≈ 9.09
9.09 ounces of pure water must be added to produce a 55% solution.