Arun purchased 30 kg of wheat at the rate of Rs. 11.50 per kg and 20 kg of wheat at the rate of Rs. 14.25 per kg. He mixed the two and sold the mixture. Approximately what price per kg should he sell the mixture to make 30% profit ?

C.P. of 50 kg wheat
= Rs. (30 × 11.50 + 20 × 14.25)
= Rs. (345 + 285)
= Rs. 630
$$\eqalign{ & {\text{S}}{\text{.P}}{\text{. of 50 kg wheat}} \cr & = 130\% {\text{ of Rs}}{\text{.630}} \cr & = {\text{Rs}}.\left( {\frac{{130}}{{100}} \times 630} \right) \cr & = {\text{Rs}}.819 \cr & \therefore {\text{S}}{\text{.P}}{\text{. per kg}} \cr & = {\text{Rs}}{\text{.}}\left( {\frac{{819}}{{50}}} \right) \cr & = {\text{Rs}}.16.38 \approx {\text{Rs}}.16.30 \cr} $$