Question

A tank is filled in 30 minutes by a pipe and in 60 minutes by pipe



b. another pipe c can emoty a full tank in 45 minutes if c is opened for 30 minutes and after that a and b are also opened then how much time tank will fully filled

Answer 1

pipe A= 30 minutes
pipe B = 60 minutes

pipe C. = empty in 45 minutes.

let total volume be X units
then 30/45X units
then 2/3 of the tank is emptied.
remaining volume = 1/3
time taken by tank A to fill = 2*30/3= 20 min
time taken by tank B to fill= 2*60/3= 40 min
then time taken = 20+40-45= 15 minutes.