6 views
In a mixture, the ratio of milk and water is $8: 7$. If 11 litres of water is mixed, then the ratio becomes $8: 9$. Find the amount of milk in the initial mixture.

(a) 63 litres

(b) 88 litres

(c) 22 litres

(d) 44 litres

Solution

Let the amounts of milk and water are $8 x$ and $7 x$.

$$\begin{array}{l} \therefore \quad \frac{8 x}{7 x+11}=\frac{8}{9} \\ \Rightarrow \quad 72 x=56 x+88 \\ \Rightarrow \quad 72 x-56 x=88 \\ \Rightarrow \quad 16 x=88 \\ \therefore \quad x=\frac{88}{16} \end{array}$$

$\therefore$ The amount of milk $=8 x$

$$\begin{array}{l} =8 \times \frac{88}{16} \\ \text { itres; Ans. } \end{array}$$

Correct option $=(\mathrm{d})$

Trick :

Milk: Water

\begin{aligned} 8: & 7 \\ 8: & 9 \\ \hline & 2=11 \end{aligned}

$\therefore$ Amount of milk $=\frac{11}{2} \times 8$

$=44$ litres: Ans

by
7.2k Points

13 views
1 Vote
6 views
1 Vote
8 views
1 Vote
7 views
12 views
1 Vote