An egg seller sells his eggs only in the packs of 3 eggs, 6 eggs, 9 eggs, 12 eggs etc., but the rate is not necessarily uniform. One day Raju (which is not the same egg seller) purchased at the rate of 3 eggs for a rupee and the next hour he purchased equal number of eggs at the rate of 6 eggs for a rupee. Next day he sold all the eggs at the rate of 9 eggs for Rs. 2. What is his percentage profit or loss?

$$\eqalign{ & {\text{CP of one egg in }}{{\text{1}}^{st}}{\text{ case}} \cr & = \frac{1}{3} = 33.33\,{\text{paise}} \cr & {\text{CP of one egg in}}\,{2^{nd}}{\text{ case}} \cr & = \frac{1}{6} = 16.66\,{\text{paise}} \cr & {\text{Average}}\,{\text{CP}} \cr & = \frac{{ {33.33 + 16.66} }}{2} \cr & = 25\,{\text{paise}} \cr & {\text{Selling}}\,{\text{price}}\,{\text{of}}\,{\text{9}}\,{\text{eggs}} \cr & = Rs.\,2 \cr & {\text{SP}}\,{\text{of}}\,{\text{one}}\,{\text{egg}} \cr & = \frac{{200}}{9} \cr & {\text{Profit}}\,{\text{or}}\,{\text{loss}} \cr & = \frac{{ {\left( {25 - {\frac{{200}}{9}} } \right) \times 100} }}{{25}} \cr & {\text{Profit}}\,{\text{or}}\,{\text{loss}} \cr & = 11.11\,({\text{loss}}) \cr} $$