New RBI Grade B 2025 Notification will come Soon! Enroll Here

    Question

    Pipe ‘X’ can fill a tank in 20 hours while pipe

    ‘Y’ can empty it in 24 hours. They were operated alternately starting with pipe ‘X’. Find the percentage of tank filled this way in 72 hours.
    A 25% Correct Answer Incorrect Answer
    B 35% Correct Answer Incorrect Answer
    C 30% Correct Answer Incorrect Answer
    D 45% Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ,

    Let the total capacity of tank be 120 units

    Efficiency of pipe ‘X’ = 120/20 = 6 units/hour

    Efficiency of pipe ‘Y’ = 120/24 = 5 units/hour

    Tank filled in 2 hours = (6 – 5) = 1 unit

    Therefore, tank filled in (2 × 36 = 72 hours) = 1 × 36 = 36 units

    Required percentage of tank filled = (36/120) × 100 = 30%

    Practice Next

    Relevant for Exams: