Question 407187
a nurse wants to add water to 30 ounces of a 10% solution of benzakonium chloride to dilute it to an 8% solution how much water must she add?

..

letx=ounces of water to add
then 30+x=ounces of diluted solution
remember, when you add water, you are adding 0% solution

10%(30)+0%(x)=8%(30+x)
3=2.4+.08x
.08x=3-2.4=.6
x=7.5 ounces
ans:
The nurse must add 7.5 ounces of water to dilute to an 8% solution