Carcass wrote:
A 400-milliliter solution is 20% alcohol by volume. If 100 milliliters of water is added, what is the new concentration of alcohol, as a percent of volume?
(A) 5%
(B) 10%
(C) 12%
(D) 12.5%
(E) 16%
Kudos for the right answer and explanation
A 400 milliliter solution is 20% alcohol by volume.20% of 400 =
80So, the original solution contains
80 milliliters of alcohol
If 100 milliliters of water is added...400 + 100 = 500
So, our NEW solution has a total volume of
500 milliliters
...what is the new concentration of alcohol, as a percent of volume?NEW concentration of alcohol =
80/
500Divide top and bottom of our fraction by 5 to get: 16/100, which is the same as 16%
Answer: E
Cheers,
Brent