Answer-Pipe ‘A’ can fill 25% of a tank in 4 hours while pipe ‘B’ takes 20 hours to...

Time taken by pipe lsquoArsquo to fill the tank 40.25 16 hours Let, the total capacity of the tank be 80 units Efficiency of pipe lsquoArsquo 8016 5 unitshour Efficiency of pipe lsquoBrsquo 8020 4 unitshour Tank filled in 14 hours 5 times 14 70 units Time taken by pipe lsquoArsquo and pipe lsquoBrsquo to fill the remaining tank 80 ndash 705 ndash 4 10 hours Therefore, total time taken 10 14 24 hours

Question

Pipe ‘A’ can fill 25% of a tank in 4 hours

while pipe ‘B’ takes 20 hours to empty fully filled tank. Pipe ‘A’ is opened alone when the tank was empty. After 14 hours, pipe ‘B’ is also opened. In how much time the tank will get filled this way?

A 34 hours

B 30 hours

C 24 hours

D 28 hours

E None of these