A vendor mixed two varieties of rice costing ₹60 per kg and ₹45 per kg in the ratio 3 : 7. If he sells the mixed variety at ₹65 per kg, then what is his gain percentage? [Give your answer correct to two decimal places.]

31.31%

The cost of first type of rice = 60

The cost of second type of rice = 45

He mixed them in the ratio of = 3 : 7

Cost of the rice per kg after mixing them = \(\frac{(60 × 3) + (45 × 7)}{3 + 7}\) =  49.5

Selling price of the rice per kg = 65

Profit% = ( 65 - 49.5) × \(\frac{100}{49.5}\) = 31.31%