The final solution will be 9 parts water and 1 part hydrogen peroxide (so that hydrogen peroxide makes up 1 of 10 parts of the solution).
Then each "part" is (16 ounces)/9 = 1 7/9 ounces.
1 7/9 ounces of hydrogen peroxide must be added to 16 ounces of water to make a 10% solution.
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<em>Check</em>
The total amount of solution is 16 +1 7/9 = 17 7/9 ounces = 160/9 ounces. The amount that is hydrogen peroxide is 16/9 ounces, so the fraction that is hydrogen peroxide is ...
