A person purchase 1 kg of tomatoes from each of 4 places at rate of 1 kg, 2 kg, 3 kg, 4 kg per rupee respectively. On an average, he has purchased x kg of tomatoes per rupee. Then value of x is-

Total quantity purchased = 4 kg
Total Money paid
$$\eqalign{ & = {\text{Rs}}{\text{. }}\left( {1 + \frac{1}{2} + \frac{1}{3} + \frac{1}{4}} \right) \cr & = {\text{Rs}}{\text{. }}\frac{{25}}{{12}} \cr} $$
? Required average
$$\eqalign{ & = \left( {4 \times \frac{{12}}{{25}}} \right){\text{ kg/rupee}} \cr & = \left( {\frac{{48}}{{25}}} \right){\text{ kg/rupee}} \cr & = 1.92{\text{ kg/rupee}} \cr} $$