Six pumps working together empty a tank in 28 min. How long will it take to empty the tank if four such pumps are working together

8pumps to to fill a tank in 1hour 30minutes. How long will it take,if only 6pumps?

Pipe A can fill a tank in 20 minutes and Pipe B can empty the same tank in 30 minutes. Find the time taken to fill the empty tank if both pipes are opened together

A tap can fill a tank in 10 minutes and another can empty it in 6 minute.If the tank is already two fifths full and both the taps are opened together,will the tank be filled or emptied? How long will it take before the tank is either filled completely or emptied completely,as the case may be?

A tap can fill a tank in 16 minutes and another can empty it in 8 minutes. If the tank is already 1/2 full and both the taps are opened together , will the tank be filled or emptied? How long will it take before the tank is either filled compoletely or emptied completely, as the case may be?

A tap having diameter 'd' cam empty a tank in 40 min . How long another tap having diameter '2d' take to empty the same tank ?

Three pumps working 8 hours a day can empty a tank in 2 day. How many hours a day must 4 pumps work to empty the tank in 1 day.

3 pumps, working 8 hours day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day? 9 b. 10 c. 11 d. 12

Pipe A can fill a tank in 30 min , while pipe B can fill the same tank in 10 min and pipe C can empty the full tank in 40 min. If all the pipes are opened together, how much time will be needed to make the tank full?