Find the cost price when the selling price is Rs. 880 and the loss % is 12%.

Given: SP = Rs. 880

Loss % = 12%

CP =?

By using the formula,

$\mathrm{Loss}\%=\frac{\mathrm{CP}-\mathrm{SP}}{\mathrm{CP}}\times 100$

$\Rightarrow 12=\frac{\mathrm{CP}-880}{\mathrm{CP}}\times 100$

$\Rightarrow 12\mathrm{CP}=100\mathrm{CP}-88000$

$\Rightarrow 88\mathrm{CP}=88000$

$\Rightarrow \mathrm{CP}=1000$

Hence, the cost price is Rs. 1000.