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

    Question

    A water tank can be filled in 20 minutes by an inlet and

    emptied in 30 minutes by an outlet. Calculate the time required to fill half of the tank with both open.
    A 54 mins Correct Answer Incorrect Answer
    B 75 mins Correct Answer Incorrect Answer
    C 30 mins Correct Answer Incorrect Answer
    D 45 mins Correct Answer Incorrect Answer

    Solution

    ATQ,

    Let total capacity of the tank be 60 litres (LCM of 20 and 30)

    Efficiency of inlet = 60 ÷ 20 = 3 litres/minute

    Efficiency of outlet = 60 ÷ 30 = -2 litres/minute

    Required time = (0.5 × 60) ÷ (3 - 2) = 30 minutes

    Practice Next

    Relevant for Exams: