Two vessels X and Y contain milk and water mixed in the ratio 4 3 and 8 1 respectively The ratio in ...........

Quantitative Aptitude (CDS) Mixture and Alligation

Two vessels X and Y contain milk and water mixed in the ratio 4:3 and 8:1 respectively. The ratio in which these two mixtures be mixed to get a new mixture containing 500/7% milk, is :

11:9

3:5

5:2

5:7

Explanation:

Let the cost of 1-liter milk be Rs.1.
Milk in the 1-liter mix. in X = 4/7 liter
C.P. of 1-liter mix. In X = Rs.4/7 liter
Milk in 1 liter mix. in Y = 8/9 liter
C.P. of 1 liter mix. In Y = Rs.8/9
Milk in 1 liter of the final mix. = ( 500/7 × 1/100 ×1 )
= 5/7
mean price = Rs.5/7
By the rule of alligation, we have:
Required ratio = ( 8/9 – 5/7 ) / ( 5/7 – 4/7 )
= 11:9