The given reversible reaction can be obtained as,
Cu2++e−→Cu+;△G∘=−0.15 F∵△G∘−nFE∘
In2++e−→In+;△G∘=+0.40F
In+→In3++2e−;△G∘=−0.84F––––––––––––––––––––––––––––––––––––––
Cu2++In2+⇌In3++Cu+;△G∘=−0.59 F––––––––––––––––––––––––––––––––––––––––––––––––––
−nFE∘=−0.59F
E∘=0.59 volt
Equilibrium constant can be calculated as,
K=antilog[nE∘0.059]
=antilog[1×0.590.059]=1010.