Two taps can fill a tank in 4 and 5 hours respectively A drain pipe can empty the tank in 3 hours If...........

Quantitative Aptitude (CDS) Pipes&cistern

Two taps can fill a tank in 4 and 5 hours respectively. A drain pipe can empty the tank in 3 hours. If all the three pipes were opened together then the tank will be filled in how much time?

60/7 hours