q4&5 pls, please provide detailed full working i am not sure how to attempt the problem. thanks

4. A gaseous mixture contains 32.9mol%He,40.7mol%N2 and 26.4mol%Ar. What is the composition of this mixture on a mass basis ? MW(He)=4.003MW(N2)=28.02MW(Ar)=39.95 5. Martian atmosphere is predominantly carbon dioxide with small amounts of other compounds. Th composition is 93.82mol%CO2,4.17mol%N2,1.73mol%Ar, 0.18mol%O2 and 0.10mol%CO. What is the average molecular weight of the gas? At a point on the surface of Mars away from the mountain regions the atmospheric pressure is 600Pa. What is the partial pressure of N2 at that point ? MW(CO2)=44.01MW(O2)=32.00MW(N2)=28.01MW(CO)=28.01MW(Ar)=39.95