solve b and c please! thanks!!!

Methane gas flows through a pipeline with a volumetric flow rate of 11ft3/s at a pressure of 123 atm and a temperature of 56F Determine the mass flow rate, in lb/s, using the: (a) ideal gas equation of state. (b) van der Waals equation. (c) Redlich-Kwong equation. Part: Your answer is correct. Determine the mass flow rate, in lb/s, using the ideal gas equation of state. m= Ib/s