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

Answer: Option A

Solution(By Examveda Team)

Let the price of the mixed variety be Rs. x per kg.
By rule of alligation, we have:

$$\eqalign{ & \therefore \frac{{20 - x}}{{x - 15}} = \frac{2}{3} \cr & \Rightarrow 60 - 3x = 2x - 30 \cr & \Rightarrow 5x = 90 \cr & \Rightarrow x = 18 \cr} $$