### Three containers whose volumes are in the ratio of 2 : 3 : 4 are full of mixture of spirit and water. In the 1st container the ratio of spirits and water is 4 : 1, in 2nd container the ratio is 11 : 4 and on the 3rd container ratio is 7 : 3. All the three mixtures are mixed in a big container. The ratio of spirit and water in the resultant mixture is ?

A. 4 : 9 B. 9 : 5 C. 11 : 4 D. 5 : 10 Answer: Option C
\begin{aligned}&\text{In 2 litres of first container,}\\ &\text { Spirit }=2 \times \frac{4}{5}=\frac{8}{5} \\ &\text { water }=2 \times \frac{1}{5}=\frac{2}{5} \end{aligned}
\begin{aligned}&\text{In 3 litres of first container,}\\ &\text { Spirit }=3 \times \frac{11}{15}=\frac{11}{5} \\ &\text { water }=3 \times \frac{4}{15}=\frac{4}{5} \end{aligned}
\begin{aligned}&\text{In 4 litres of first container,}\\ &\text { Spirit }=4 \times \frac{7}{10}=\frac{14}{5} \\ &\text { water }=4 \times \frac{3}{10}=\frac{6}{5} \end{aligned}
\begin{aligned}&\text{∴ Required ratio}\\ &=\left(\frac{8}{5}+\frac{11}{5}+\frac{14}{5}\right):\left(\frac{2}{5}+\frac{4}{5}+\frac{6}{5}\right) \\ &=\frac{33}{5}: \frac{12}{5} \\ &=33: 12 \\ &=11: 4 \end{aligned}