Calculate the value of the electrode potential at $298 \mathrm{K}$ of a $\mathrm{Ni}\left(\mathrm{s}\right)/{\mathrm{Ni}}^{2+}\left(\mathrm{aq}\right)$ electrode that has a concentration of ${\mathrm{Ni}}^{2+}\left(\mathrm{aq}\right)$ ions of $1.5 \mathrm{mol} {\mathrm{dm}}^{-3}$. ${\mathrm{E}}^{°}=-0.25 \mathrm{V}$

A half-cell containing $\mathrm{Sn}$ in $1.00 \mathrm{mol} {\mathrm{dm}}^{-3}$ ${\mathrm{Sn}}^{2+}$ ions is connected to another half-cell containing $\mathrm{Zn}$ in $1.00 \mathrm{mol} {\mathrm{dm}}^{-3}$ ${\mathrm{Zn}}^{2+}$ ions at $298 \mathrm{K}$. 

${\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\stackrel{ }{\rightleftharpoons }\mathrm{Zn}\left(\mathrm{s}\right): {\mathrm{E}}^{°}=-0.76 \mathrm{V}$ and 

${\mathrm{Sn}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\stackrel{ }{\rightleftharpoons }\mathrm{Sn}\left(\mathrm{s}\right): {\mathrm{E}}^{°}=-0.14 \mathrm{V}$

Which one of the following is the value of $\mathrm{E}$ when the concentration of both the ${\mathrm{Zn}}^{2+}$ ions and ${\mathrm{Sn}}^{2+}$ are changed to $0.1 \mathrm{mol} {\mathrm{dm}}^{-3}$?