A dry fruit seller purchased 3 kinds of nuts at the rate of Rs. $100$/kg, Rs. $80$/kg and Rs. $60$/kg. He then mixed them, respectively, in the ratio $3:4:5$ by weight and sold the same to a customer at $50$% profit. The price at which he sold to the customer is
- Rs. $110$
- Rs. $90$
- Rs. $70$
- None of these