How many liters of water should be added to 18 liters of a 14% bleach solution so that the resulting solution contains only 10%
Bleach content of constituents = bleach content of final solution
.14(18) = .1 (18 + x). Solve for x, the amount a
of water required
Just to expand upon EP's answer
Let x represent the number of liter of water to be added.:
The percentage of bleach solution in pure water is 0.00.
The final percent must be between the percentages of the parts.
The final amount is found by adding the amounts of the parts together.
(percent · amount) + (percent · amount) = (final percent · final amount)
0.00 · x + 0.14 · 18 = 0.10 · (x + 18)
Then finish, as EP states.