Pipe A and B can empty a full tank in 18 hours and 24 hours, respectively. Pipe C alone can fill the tank in 36 hours. If the tank is 5/6 full and all the three pipes are opened together, then in how many hours will the tank be emptied?
1
\(10\frac{1}{2}\)
2
\(12\frac{1}{2}\)
3
10
4
12