x liters of orange juice
y liters of carrot juice
\(x+y\) liters - the total volume of the mixture
Percentage of orange juice per volume : \(\frac{x}{x+y}\)
(1) \(x+2\) liters of orange juice
\(y-2\) liters of carrot juice
\(x+2+y-2=x+y\) liters of the mixture
Percentage of orange juice per volume : \(\frac{x+2}{x+y}\)
The percentage of orange juice by volume in the mixture would double, so \(\frac{x+2}{x+y}\)=\(\frac{2x}{x+y}\)
After some claculations we receive the value of x, \(x=2\)
However, we can't find y. So this statement alone if not sufficient
(2) \(x+\frac{y}{2}\) liters of orange juice
\(\frac{y}{2}\) liters of carrot juice
\(x+\frac{y}{2}+\frac{y}{2}=x+y\) liters of the mixture
Percentage of orange juice per volume:
\(\frac{x+\frac{y}{2}}{x+y}\)
The percentage of orange juice by volume in the mixture would double, so \(\frac{x+\frac{y}{2}}{x+y}=\frac{2x}{x+y}\)
We can't solve this equation without knowing value of x or y. So this statement alone is not sufficient.
However, we know the value of x, we plug it in and find that \(y=4\)
\(\frac{2}{2+4}=0,(3),\) so around 33% of mixture by volume is orange juice
Thus, the right answer is C. BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked.