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