Pipe A can fill a tank in 12 hours. Pipe B can fill 33\(\frac{1}{3}\)% part of the same tank in 6 hours, whereas pipe C can empty full tank in x hours. When all the three pipes are opened together, \(\frac{13}{15}\) part of tank is filled in 12 hours. How much time (in hours) will A and C together take to fill 40% part of the tank?