Menu
Home / Arithmetic Aptitude / Pipes and Cistern :: Discussion

Discussion :: Pipes and Cistern

  1. Two pipes A and B can fill a tank in 15 minutes and 20 minutes respectively. Both the pipes are opened together but after 4 minutes, pipe A is turned off. What is the total time required to fill the tank?

    2. A.

    10 min. 20 sec.
    B.

    11 min. 45 sec.
    C.

    12 min. 30 sec.
    D.

    14 min. 40 sec.

    View Answer

    Workspace

    View Answer

    Answer : Option D

    Explanation :

    Part filled in 4 minutes =4 [\( \frac { 1 } { 15 }\)+\( \frac { 1 } { 20 }\)] =\(\frac { 7 } { 15}\)

     

    Remaining part =[1- \(\frac { 7 } { 15}\)]=\(\frac { 8 } { 15}\)

     

    Part filled by B in 1 minute =\(\frac { 1 } { 20 }\)

     

    \(\frac { 1 } { 20 }\):\(\frac { 8 } { 15}\)::1:x

     

    x =[\(\frac { 8 } { 15}\)x1 x20]=10 \(\frac {2 } { 3 } \) min = 10 min. 40 sec.

     

     The tank will be full in (4 min. + 10 min. + 40 sec.) = 14 min. 40 sec.

     

Write your comments here:

Be The First To Comment