The cost of Type 1 rice is Rs. 15 per kg and Type 2 rice is Rs. 20 per kg. If both Type 1 and Type 2 are mixed in the ratio of 2 : 3, then the price per kg of the mixed variety of rice is:_______?
A. Rs. 18
B. Rs. 18.50
C. Rs. 19
D. Rs. 19.50