Bunuel
A mixture consists of liquids A, B, and C in the ratio of 1:4:6, respectively. What is the total volume of the mixture in liters?
(1) If the amount of liquid A were doubled, the ratio would be 1:2:3.
(2) If 5 liters of liquid A were added, the ratio would be 1:2:3.
Solution: Let us assume the value of A, B and C in the mixture to be \(x, 4x\) and \(6x\) respectively.
Total volume \(= x+4x+6x=11x\). To get the volume
we will need the value of \(x\).
Statement 1: When we double the amount of liquid A, we get the volume of A, B and C in the mixture \(= 2x, 4x\) and \(6x\) respectively.
Now \(2x, 4x\) and \(6x\) is already in the ratio \(1:2:3\).
Thus
statement 1 alone is not only insufficient but also redundant. We can eliminate options A and D.
Statement 2: When we add 5 liters of liquid A, volume of A, B and C in the mixture \(= x+5, 4x\) and \(6x\).
The ratio of these volumes are given to us as \(1:2:3\). So, let us assume the volumes to be \(y, 2y\) and \(3y\) respectively.
So, we can write \(6x=3y\)
\(⇒ x=\frac{y}{2}\).......(i)
Upon plugging this value in \(x+5=y\), we get:
\(⇒ \frac{y}{2}+5=y\)
\(⇒ y-\frac{y}{2}=5\)
\(⇒ \frac{y}{2}=5\)
\(⇒ y=10\)
PLuggin this in eq i, we get
\(x=\frac{10}{2}=5\)
This is what we needed to get our answer.
Statement 2 alone is sufficient.
Hence the right answer is
Option B.