A nurse wants to add water to 30 ounces of a 10% solution of benzalkonium chloride to dilute it to an 8% soultion. How much water nust she add?(hint water is 0% benzalkonium chloride)

Answer 1

Benzalk:
.08(W+30)=.10*30
that says 8percent of the total solution has the same amount of benzyl as did the original solution.
Solve for W.

Answer 2

7.5 oz