Question 12 Marks
A vessel contains a mixture of two liquids X and Y in the ratio 3 : 5. 8 litres of mixture are drawn off from the vessel and 8 liters of liquid X is filled in the vessel. If the ratio of liquids X and Y is now becomes 7: 10, how many litres of liquids X and Y were contained by the vessel initially?
Answer
View full question & answer→Let initially liquids X and Y be 3x litres and 5x litres respectively in the vessel.
After drawing off 8 litres of mixture:
Quantity of liquid $X$ left in the mixture $=3 x-\frac{3}{8} \times 8=(3 x-3)$ litres
Quantity of liquid $Y$ left in the mixture $=5 x-\frac{5}{8} \times 8=(5 x-5)$ litres
Further 8 litres of liquid X are mixed in the mixture.
So, quantity of liquid X in the mixture = (3x - 3 + 8) litres = (3x + 5) litres
According to given, $\frac{7}{10}=\frac{3 x+5}{5 x-5}$.
$\begin{array}{l}\Rightarrow 35 x-35=30 x+50 \Rightarrow 5 x=85 \\ \Rightarrow x=17\end{array}$
Hence, the quantity of liquid X = 3 x 17 = 51 litres and the quantity of liquid Y = 5 x 17 = 85 litres initially.
After drawing off 8 litres of mixture:
Quantity of liquid $X$ left in the mixture $=3 x-\frac{3}{8} \times 8=(3 x-3)$ litres
Quantity of liquid $Y$ left in the mixture $=5 x-\frac{5}{8} \times 8=(5 x-5)$ litres
Further 8 litres of liquid X are mixed in the mixture.
So, quantity of liquid X in the mixture = (3x - 3 + 8) litres = (3x + 5) litres
According to given, $\frac{7}{10}=\frac{3 x+5}{5 x-5}$.
$\begin{array}{l}\Rightarrow 35 x-35=30 x+50 \Rightarrow 5 x=85 \\ \Rightarrow x=17\end{array}$
Hence, the quantity of liquid X = 3 x 17 = 51 litres and the quantity of liquid Y = 5 x 17 = 85 litres initially.