SOLUTION: Hi! Barbara has a bucket that holds 18 fl oz. She mixes 14.4 fl oz of water and 3.6 oz of ammonia to make a cleaning solution. She then decides to replace a portion of the cleanin

Question 679432: Hi!
Barbara has a bucket that holds 18 fl oz. She mixes 14.4 fl oz of water and 3.6 oz of ammonia to make a cleaning solution. She then decides to replace a portion of the cleaning solution to create a cleaning solution with 25% ammonia. How much cleaning solution should be replaced by ammonia?
So far I have figured out that 14.4 fl oz is 80% of 18 fl oz and 3.6 fl oz is 20 % of 18 fl oz. Are the percentages part of the concentration? If not, what are they?

Answer by KMST(5328) (Show Source): You can put this solution on YOUR website!
The solution she has in the bucket has 80% water (as you found out), including 14.4 fl oz. water in a total of 18 fl oz. solution.
Barbara will need to add ammonia, but only after removing some ( fl oz.) of the solution she has in the bucket.
If Barbara wants an 18 fl oz. bucket full of 25% ammonia, she will need to have in that bucket
fl oz. ammonia (25% ammonia) and
fl oz. water (75% water).
Barbara will have to start by removing some of that 80% water solution to end up with just 13.5 fl oz. water in the bucket.
Removing fl oz. of solution, gets rid of fl oz. of water,
leaving fl oz. of water.
Since the amount of water needed is fl oz., our equation is

--> --> --> --> fl oz.

RELATED QUESTIONS
During a science experiment, Claire created an 18% alcohol solution by mixing 4 fluid... (answered by Boreal)

Jaiden wants to make a 20% saline solution. She had already poured 9 fl. oz. of pure... (answered by Boreal)

During a science experiment, Jean created a 36% alcohol solution by mixing 11 fluid... (answered by richwmiller)

During the science experiment, Ethan created a 20% alcohol solution by mixing 4 fluid... (answered by richwmiller)

Eugene wants to make a 14% sugar solution. He has already poured 9 fl. oz. of pure water (answered by jorel1380)

how many fl. oz. of a 20% acid solution must be mixed with 9 fl. oz. of a 40% acid... (answered by TimothyLamb)

Finding the grams of sugar in 12 fl oz of lemonade. The mixture for 128 fl oz was 24 oz... (answered by FrankM)

Can you hlep me figure this out? Mark uses 1pt 9 fl oz and then 2 pt 10 fl oz from a... (answered by fractalier)

During a science experiment, Nico created an 18% alcohol solution by mixing 7 fluid... (answered by josgarithmetic,richwmiller)