24 pumps are connected to a tank. Some of them are inlet pumps and the others are outlet pumps. Each of the inlet pumps an fill the tank in 16hours and each of the outlet pumps can empty the tank completely in 12hours. If all the pumps are kept open, the empty tank gets filled in 48 hours. How many inlet pumps are there? A) 16 B) 18 C) 17 D) 14