Question

The ratio of spirit and water in two mixtures of 20 liters and 36 litres is 3 : 7 and 7 : 5 respectively. Both the mixtures are mixed together. Now the ratio of the spirit and water in the new mixture is

• A. 25 : 29
• B. 9 : 10
• C. 27 : 29
• D. 27 : 31

Answer 1

Answer: (C)

27 : 29

According to the question,

Mixture $-1=20$ litres

Mixture $-2=36$ litres

In Mixture −1

Ratio=$\frac{3}{7}$ total $10$ units.

In Mixture −2

ratio=$\frac{7}{5}$ total $12$ units

10 units$\to$20 litres

1 unit $\to$2 litres

12 units $\to$ 36 litres

1 unit$\to$3 litres

$\therefore$ In Mixture −1

ratio =$\frac{3\times 2}{7\times 2}=\frac{6}{14}$

$\therefore$ In Mixture −2

ratio=$\frac{7\times 3}{5\times 3}=\frac{21}{15}$$

Ratio of spirits and water = $\frac{6+21}{14+15}=\frac{27}{29}=27:29$