In a meter Bridge experiment resistance $x$ is connected in the right gap. When $R_1$ and $R_2$ are connected in the left gap separately the balance points are $40\mathrm{ }\mathrm{c}\mathrm{m}$ and $50\mathrm{ }\mathrm{c}\mathrm{m}$ respectively from the left end. Now if both $R_1\mathrm{ }\&\mathrm{ }{R}_2$ are connected in series in the left gap with $x$ in the right gap then what will be the new balance point from the left end (in $\mathrm{cm}$)?