Q: 19 (NDA-II/2018)

A stainless steel chamber contains Ar gas at a temperature T and press P. The total number of Ar atoms in the chamber is n. Now Ar gas in the chamber is replaced by CO2 gas and the total number of CO2 moleucules in the chamber is n/2 at the same temperature T. The pressure in the chamber now is P'.
Which one of the following relations holds true? (Both the gases behave as ideal gases)