Conducting Spheres...?

Question

Hey everyone... i'm stuck on two problems.. if anyone could help me out that would be great... thanks in advance!

A conducting sphere radius R has a total charge of Q on its surface, how much charge will there be on this sphere's surface after it is brought into contact with another, initially uncharged conducting sphere of radius 2R?

and...

A conducting sphere of radius R with a charge Q on its surface and a potential V inside is brought into contact with another initially uncharged conducting sphere of radius 4R. After reaching equillibrium, the potential inside the larger sphere becomes?

Answer 1

A1 = 4πR^2
A2 = 4π(2R)^2 = 16πR^2
A1/(A1 + A2) = 4πR^2/(4πR^2 + 16πR^2)
A1/(A1 + A2) = 4πR^2/(4πR^2(1 + 4)) = 1/5
Qf = Q/5

and

V = 4V/5