Question

    A 150 ml solution consists of alcohol and water in a

    ratio of 2:3. A portion of this mixture is removed, containing 18 ml of water, and then 6 ml of alcohol is added back to the remaining solution. Determine the new ratio of alcohol to water in the final mixture.
    A 5:7 Correct Answer Incorrect Answer
    B 1:2 Correct Answer Incorrect Answer
    C 3:4 Correct Answer Incorrect Answer
    D 8:9 Correct Answer Incorrect Answer

    Solution

    Initial quantity of alcohol in the mixture = (2/5) × 150 = 60 ml

    So, the initial quantity of water = 150 – 60 = 90 ml

    The percentage of water removed = (18/90) × 100 = 20%

    Which means 20% of the mixture is removed.

    So, the new quantity of alcohol in the mixture = 0.8 × 60 = 48 ml

    New quantity of water = 90 – 18 = 72 ml

    ATQ, Final quantity of alcohol in the mixture = 48 + 6 = 54 ml

    So, the required ratio = 54:72 = 3:4

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