Pipe A can fill a tank in 2 hours and Pipe B can fill the same tank in 3 hours. Capacity of tank is 60 litres. If Pipe A filled the tank for 1/2 hours, then in how many hours the remaining part of the tank will be filled by pipe B?
1
7/4 hours
2
9/4 hours
3
5/2 hours
4
3/2 hours
5
None of these