Find the density and specific gravity of the following

Question

(a) SO2 at 700F and 1 atm
(b) Mixture of 10 mole% CH4 and 90 mole% argon at 5400C and 28.9 inch Hg
(c) Air containing 0.045 lbm H2O per pound mass of dry air at 2000F and 29.7 in Hg absolute pressure