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

    Question

    In a container containing 120 liters of pure petrol, 40

    liters of petrol are drawn and replaced with the same quantity of diesel. This process is repeated twice more. Determine the approximate quantity of petrol remaining in the container.
    A 15.2 Correct Answer Incorrect Answer
    B 55.25 Correct Answer Incorrect Answer
    C 35.5 Correct Answer Incorrect Answer
    D 20.4 Correct Answer Incorrect Answer
    E none of these Correct Answer Incorrect Answer

    Solution

    ATQ, Quantity of petrol left in the container = y{1 – (a/y)}n Where, y = original quantity of petrol, a = quantity of petrol replaced and n = number of times the process is repeated. Therefore, quantity of petrol left in the container = 120{1 – (40/120)}3 = 35.55 ~ 35.5 litres

    Practice Next

    Relevant for Exams: