I'm going to need some help getting this problem started

Calculate E for the following electrochemial cell at 25 degrees Celsius

Pt(s) ! Sn^2+(aq, 0.50M), Sn^4+(aq, 0.50Mz0 !! I^-(aq, 0.15M) ! AgI(s) !Ag(s) given the following standard reduction potentials

AgI(s) + e^- ==> Ag(s) + I^-(aq) E naught = -0.15V

Sn^4+(aq) + 2e^- ==> Sn^2+)aq) E naught = +0.15V

What I would do is to calculate E for the Sn^+2 to Sn^+4 at the concns listed, do the same for the I^- to AgI couple, then add the oxdn half to the redn half. That will give you the cell potential.