AbhishekRyu wrote:How many ounces of water must be added to 10 ounces of 3 % alcohol and water solution to reduce the solution to 1% alcohol.
A)5
B)10
C)15
D)20
E)30
Alcohol percentage in the original solution: 3%.
Alcohol percentage in the added water: 0%.
Alcohol percentage in the mixture: 1%.
Let S = the original solution and W = the added water.
The following approach is called ALLIGATION -- a very efficient way to handle MIXTURE PROBLEMS.
Step 1: Plot the 3 percentages on a number line, with the percentages for S and W (3% and 0%) on the ends and the percentage for the mixture (1%) in the middle.
S 3%----------1%-----------0% W
Step 2: Calculate the distances between the percentages.
S 3%----
2-----1%----
1-----0% W
Step 3: Determine the ratio in the mixture.
The ratio of original solution to added water is equal to the RECIPROCAL of the distances in red.
S:W = 1:2 = 10:20.
The resulting ratio indicates that the 10 ounces of original solution must be combined with 20 ounces of water.
The correct answer is
D.
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