Question

    In a solution, the ratio of milk to water is 4:5. If 6

    litres of milk and 12 litres of water are added, the new ratio becomes 5:7. What was the original quantity of the solution?
    A 54 litres Correct Answer Incorrect Answer
    B 67 litres Correct Answer Incorrect Answer
    C 90 litres Correct Answer Incorrect Answer
    D 70 litres Correct Answer Incorrect Answer

    Solution

    ATQ,

    Let initial milk = 4y, water = 5y

    Then, (4y + 6):(5y + 12) = 5:7

    ⇒ 7(4y + 6) = 5(5y + 12)

    ⇒ 28y + 42 = 25y + 60

    ⇒ 3y = 18 ⇒ y = 6

    Initial quantity = 4y + 5y = 9y = 9 × 6 = 54 litres

    Practice Next