Two kinds of rice, 1st costs Rs.13 per kg and 2nd costs Rs.19 per kg are mixed together. Find the ratio in which the 2 types are mixed so that the mixture costs Rs.14.2 per kg?

A. 3:1
B. 4:1
C. 3:4
D. 4:3
Let the total quantity of mixture be 1. If quantity of 1st type is x then quantity of the 2nd type will be (1-x)
Therefore, 13x + 19(1-x) = 14.2
13x -19x + 19 = 14.2
4.8 = 6x
x = 0.8 ; (1-x) = 0.2
Therefore, the ratio is 0.8 : 0.2 = 4:1