Half-cell / reduction potential?

[eraemia]

Could anyone give me some pointers regarding this problem?

Half-cell Xn+/X is connected with half-cell Yn+/Y and the potential difference is found to be 0.12V with Y being the positive electrode. Yn+/Y is connected with Cu2+ and the potential difference is found to be 0.13V with Cu being the positive electrode. If Cu2+ + 2 e- right arrow Cu is assigned the potential 0.34V versus the standard hydrogen electrode, what is the reduction potential of Xn+ + n e- right arrow X relative to the standard hydrogen half-cell?

My tentative solution is 0.12 V + 0.13 V = 0.25 V. Does that look right?

Thanks!

 

[AbedeuS]

Whats all this Xn+/X malarchy? Is that the representation of the half cell? If so please make it slightly more clear what's being read my understanding is:

X|X+||Y+|Y

but I am not really getting it