Hi, I am having some trouble with the following question: You (mass 70.1 kg) decide to take off--literally--with a helium balloon of mass 31.6 kg. The densities of air and helium are air = 1.321 kg/m3 and helium = 0.179 kg/m3. What volume of helium is needed to levitate you and the balloon? I think that you use the buoyant force equations, but I am not sure how. I tried doing it like this: F(buoy)=density(fluid)*V'*g or (101.7*9.81)=(1.321*V'*9.81) and solved for V' and got V'=76.987 m^3 but this is not correct. I cannot figure out how to do this problem, any help would be appreciated. Thanks!!