How to calculate Payload of a Balloon?

Payload of a Balloon if defined as maximum mass which a Balloon can carry with in it upward direction.

If V is the volume of Balloon , d_out is the density of out side air , d_in is the density of gas inside of Balloon  and Maas of Balloon is m then

Payload= [d_out × V]- [d-in×V+m]

Related Questions;

(1) Calculate payload of a balloon having volume 100 litre. It is filled with helium gas at 0.2486 atm pressureand 300K. Density of air is 1.3 gm/litre and mass of material of balloon is 20 gm.

(2) A balloon of diameter 20 m weighs 100 kg. Calculate its paylod if it is filled with helium at 1.0 atm and 27 ∘ C. Density of air is 1.2 kg m −3 .(R=0.082 dm 3 atm K −1 mol −1 ).