A 12% stock yielding 10% is quoted at:

$$\eqalign{ & {\text{To}}\,{\text{earn}}\,{\text{Rs}}{\text{.}}\,{\text{10,}}\,{\text{money}}\,{\text{invested}} \cr & = Rs.\,100. \cr & {\text{To}}\,{\text{earn}}\,{\text{Rs}}{\text{.}}\,{\text{12,}}\,{\text{money}}\,{\text{invested}} \cr & = Rs.\,\left( {\frac{{100}}{{10}} \times 12} \right) = Rs.\,120 \cr & \therefore {\text{Market}}\,{\text{value}}\,{\text{of}}\,Rs.\,100\,{\text{stocks}} = Rs.\,120 \cr} $$