Two blends of a commodity costing Rs. 35 and Rs. 40 per kg respectively are mixed in ratio 2 : 3 by weight. If one-fifth of mixture is sold at Rs. 46 per kg and remaining at rate Rs. 55 per kg, profit percent is -

Let first blend is 2 kg and second blend is 3 kg.
$$\eqalign{ & {\text{Total cost price }}{\text{ }} \cr & = \left( {35 \times 2} \right) + \left( {40 \times 3} \right) \cr & = 70 + 120 \cr & = {\text{Rs}}{\text{. 190}} \cr & {\text{Total selling price }} \cr & {\text{ = }}\left( {{\text{ }}1 \times 46} \right) + \left( {4 \times 55} \right) \cr & = 266\left[ {\frac{1}{5}{\text{ of 5kg = 1kg}}} \right] \cr & \therefore {\text{Profit percent }} \cr & \Rightarrow \frac{{{\text{Total profit}}}}{{{\text{Total cost price}}}} \times 100 \cr & \Rightarrow \frac{{\left( {266 - 190} \right)}}{{190}} \times 100 \cr & \Rightarrow \frac{{76}}{{190}} \times 100 \cr & \Rightarrow 40\% \cr} $$