SSC CPO SI and ASI 2015 Paper

(4) Let there be 3 litres, 2 litres and 1 litre of mixtures in the three vessels 1, 2, and 3, respectively.From vessel- 1 litre of mixture is taken, in which milk is $\frac{5}{7} l$ andwater is $\frac{2}{7} l$. From vessel-2, 1 litre of mixture is taken, in which milk is $\frac{4}{5}l$ and water is $\frac{1}{5}l$ From vessel-3, $\frac{1}{7}$ litre of mixture is taken, in which milk is $\frac{1}{7} \times \frac{4}{5} = \frac{4}{35} l$ and water is $\frac{1}{7} \times \frac{1}{5} = \frac{1}{35} l$Total quantity of the new mixture$=1+1+\frac{1}{7} = \frac{15}{7} l$Percentage of water in the new mixture $= \frac{ \frac{2}{7} + \frac{1}{5} + \frac{1}{35} }{ \frac{15}{7} } \times 100$$= \frac{ \frac{18}{35} }{ \frac{15}{17} } \times 100 = \frac{18}{75} \times 100 = 24\%$