Aptitude Hack#24(19-3-19)

Question:
A mixture of 85 kg contains milk and water in the ratio 27: 7. How much more water is to be added to get a new mixture containing milk and water in the ratio 3:1?

A) 5 kg     
B)6.5 kg       
C) 7.5 kg  
D) 8 kg


Answer: A) 5 kg

Explanation:

 Milk in 85 kg of mix = 85* (27/34) = 135/2 kg.

    Water in it = 85-135/2 = 35/2 kg.

 Let x kg of water be added to it.
Then,
 (135/2)/(35/2 + x) = 3/1;  135/(35 +2x) =3/1;           
105 + 6x = 135  
6x = 30;

x = 5      
    The quantity of water to be added = 5 kg
Option a).