Answer:
9%
Step-by-step explanation:
Let us assume that the original alcohol solution is x%.
So, when water and x% alcohol solution are mixed in the ratio 3 : 2, we will obtain a solution of 18% alcohol.
If water and x% alcohol solution are mixed in amount 3a and 2a amount, then we can write the equation as
[tex]\frac{2a\times \frac{x}{100} }{3a + 2a} = \frac{18}{100}[/tex]
⇒ [tex]\frac{2x}{5 \times 100} = \frac{18}{100}[/tex]
⇒ x = 45%
Now, water and 45% solution of alcohol are mixed in the ratio of 4 : 1, then the % of resulting alcohol solution will be
[tex]\frac{1 \times \frac{45}{100} }{4 + 1}\times 100 = 9%[/tex] (Answer)
