Indian Institute of Foreign Trade 2010 Solved Paper

Let the capacity of the tank be 60 litres.
Capacity of the first pipe = 12 l/hr
Capacity of the second pipe = 6 l/hr
Capacity of the third pipe = 4 l/hr
In 2 hrs, first pipe fills (9+12)l=21l
In 2 hrs, second pipe fills (4.5+6)=10.5l
In 2 hrs, third pipe fills (16/3) l
In 2 hrs, tank filled =(21+10.5+5.33)l=36.83l
Tank left to be filled =(60−36.83)l=23.17l
Time required =(

23.17

22

)hr=1.05hrs
Total time =3.05 hrs
Hence, option C is the correct answer.