Question

In a mixture of 72 litres of alcohol and water mixed in the ratio 11:1, find the amount of water that should be added such that alcohol and water are in the ratio 9:1

Answer 1

hi..
72 in 11:1 is 66:6
so 6 litres of water. lets add x ltrs more 
so (6+x)/(72+x) = 1/(1+9) 
60+10x=72+x.......9x=12...x=4/3

Answer 2

Answer:

1.33 liters

Step-by-step explanation:

Total amount of mixture = 72 liters

The ratio of alcohol and water is 11:1

So, Amount of alcohol  =$\frac{11}{12} \times 72$

                                       = 66

Amount of water = 72-66 = 6 liters

Now let x be the amount of water that should be added such that alcohol and water are in the ratio 9:1

So,$\frac{66}{6+x}=\frac{9}{1}$

$66=54+9x$

$66-54=9x$

$12=9x$

$\frac{12}{9}=x$

$1.33=x$

Hence 1.33 liters of water that should be added such that alcohol and water are in the ratio 9:1