A cistern is filled by one tap in 12 minutes and another can empty it in 10 minutes.If second tap is opened 3 minutes after the first,in what time more will the cistern be emptied?

Asked by Dibyendu | 4th Nov, 2017, 08:47: AM

Expert Answer:

Pipes and Cistern:

begin mathsize 16px style Part space of space cisterm space filled space by space one space tap space in space 1 space minute equals 1 over 12
Part space of space cistern space emptied space by space second space tap space in space 1 space min equals 1 over 10
Part space of space cistern space emptied space when space both space the space taps space are space opened equals 1 over 10 minus 1 over 12 equals 2 over 120 equals 1 over 60
Part space filled space by space one space tap space in space 3 space minutes equals 3 cross times 1 over 12 equals 1 fourth
Therefore comma space time space required space to space empty space the space cistern
equals fraction numerator 1 fourth over denominator 1 over 60 end fraction
equals 15 space minutes end style

Answered by Rashmi Khot | 4th Dec, 2017, 03:06: PM