A shopkeeper sells sugar in such a way that the selling price of 950g of sugar is the same s the cost price of 1 kg of sugar. What is his gain percent?

$$\eqalign{ & {\text{Sell}}\,{\text{sugar}} \cr & = 950g\,{\text{instead}}\,{\text{of}}\,1000g \cr & {\text{Profit}}\,{\text{in}}\,{\text{sugar}} \cr & = 1000 - 950 = 50g \cr & {\text{Now}},\,\% \,{\text{profit}} \cr & = \frac{{ {50 \times 100} }}{{950}} = 5 {\frac{5}{{19}}} \% \cr & \cr & {\text{Short - cut}}: \cr & \% \,{\text{profit}} \cr & = {\frac{{{\text{Goods}}\,{\text{lef}}t}}{{{\text{Goods}}\,{\text{sold}}}}} \times 100 \cr & = {\frac{{50}}{{950}}} \times 100 \cr & = 5 {\frac{5}{{19}}} \% \cr} $$