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:

Answer: Option A

Explanation:

Let the price of the mixed variety be Rs. x per kg.

By rule of alligation, we have:

Cost of 1 kg of Type 1 riceCost of 1 kg of Type 2 rice
Rs. 15	Mean Price Rs. x	Rs. 20
(20 - x)		(x - 15)

	(20 - x)	=	2
	(x - 15)		3

60 - 3x = 2x - 30

5x = 90

x = 18.