Bhanu Chaudhary
Poll
Professional
Asked: 2022-03-08T14:40:50+05:30

A tank can be filled by two pipes in 20 minutes and 30 minutes respectively. When the tank was empty, the two pipes were opened. After some time, the first pipe was stopped and the tank was filled in 18 minutes. After how much time of the start the first pipe stopped?

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A tank can be filled by two pipes in 20 minutes and 30 minutes respectively. When the tank was empty, the two pipes were opened. After some time, the first pipe was stopped and the tank was filled in 18 minutes. After how much time of the start the first pipe stopped?

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    1 Answer

    1. Professional

      Correct Answer: 8 minutes

      1/20+1/30 = 3+2/60

       

       

      According to questions, Pipe ‘A’ is closed after some time. and Tank is filled in 18 miuntes so B started filling the tank in beginning and worked till last i.e 18 minutes

       

      So,2×18= 36 units is filled

       

      Work left = 60−36=24 units

       

      This 24 units must be filled by ,Pipe A in beginning.

       

      It can flll it in 24/3 = 8 minutes

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