Question

    A hemispherical tank full of water is emptied by a pipe

    at the rate of 23.1 litres per second. How much time (in hours) will it take to empty 3/4  th part of the tank if the internal radius of the tank is 21 m?
    A 1575/8 Correct Answer Incorrect Answer
    B 210 Correct Answer Incorrect Answer
    C 175/6 Correct Answer Incorrect Answer
    D 175/2 Correct Answer Incorrect Answer

    Solution

    The volume of the hemispherical tank is  3/4 × 22/7 × 21 × 21 × 21 21829.5 m3 The capacity of the tank is  21829.5× 1000 L 21829500 L So,  Time taken by the pipe emptied 2/3 part of the tank is  (3/4 × 21829500) ÷ 23.1sec 708750 sec Time in hours  708750/3600 (1575/8) hours  ∴ The required time is (1575/8) hours

    Practice Next