Three closed vessels A, B and C are at the same temperature T and contain gases which obey Maxwellian distribution of velocities. Vessel A contain O2, B only N2 and C mixture of equal quantities of O2 and N2. If the average speed of the O2 molecules in the vessel A is V1, that of N2 molecules in the vessel B is V2, the average speed of the O2 molecules in vessel C is