Source: e-GMAT
A solution consists of only water and alcohol such that the ratio of alcohol to water in the solution is 7:3. How much amount of water should be added to the solution (in milliliters) so that the resulting solution contains 60% alcohol?
1. Total quantity of the resulting solution is 350 milliliters.
2. The original solution contains 10.5 milliliters of alcohol for every 4.5 milliliters of water.
The OA is A.
The Prime Sum of an integer XX greater than 1 is the sum of
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Given: Ratio of alcohol to water in the solution is 7 : 3swerve wrote:Source: e-GMAT
A solution consists of only water and alcohol such that the ratio of alcohol to water in the solution is 7:3. How much amount of water should be added to the solution (in milliliters) so that the resulting solution contains 60% alcohol?
1. Total quantity of the resulting solution is 350 milliliters.
2. The original solution contains 10.5 milliliters of alcohol for every 4.5 milliliters of water.
The OA is A.
Question: How much water should be added to the solution so that the resulting solution contains 60% alcohol?
Say alcohol = 7x ml and water = 3x ml and y ml water is added to make the solution containing 60% alcohol.
=> Alcohol / (Water + Additional water) = 60%
7x / (3x + y) = 3/5
=> 5x = 3y
If we get the value of x, we get the answer.
Let's take each statement one by one.
1. Total quantity of the resulting solution is 350 milliliters.
=> 7x + 3x + y = 10x + y = 350
From 10x + y = 350 and 5x = 3y, we can get the unique value of y. Sufficient.
2. The original solution contains 10.5 milliliters of alcohol for every 4.5 milliliters of water.
Alcohol : Water : : 10.5 : 4.5
Alcohol : Water : : 105 : 45
Alcohol : Water : : 7 : 3
This is the same information that we know from the question. No additional information. Insufficient.
The correct answer: A
Hope this helps!
-Jay
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