The ratio of milk to water in 80 litres of a mixture is 7 : 3. The water (in litres) to be added to it to… · ABC26GN3120
Subject: General Aptitude · Chapter: Ratio and Proportion · Exam: S.S.C. 2006
The ratio of milk to water in 80 litres of a mixture is 7 : 3. The water (in litres) to be added to it to make the ratio 2 : 1 is
(a)4
(b)5
(c)6
(d)8
Answer
Answer (as printed): A
Explanation
Quantity of milk $=\left(80 \times \frac{7}{10}\right)$ litres $=56$ litres. Quantity of water $=(80-56)$ litres $=24$ litres. Let the quantity of water to be added be $x$ litres. Then, $\frac{56}{24+x}=\frac{2}{1} \Rightarrow 48+2 x=56 \Rightarrow 2 x=8 \Rightarrow x=4$.
Explanation as extracted from the printed page; notation may be imperfect.