Total reaction of Cu/Ag galvanic cell:

• a$\ce{Cu + 2Ag+ -> Cu^2+ + 2Ag}$
• b$\ce{2Ag + Cu^2+ -> 2Ag+ + Cu}$
• c$\ce{Cu + Ag -> CuAg}$
• d$\ce{Cu + 2Ag -> CuAg2}$