Question

Write the following as an expression: How much water do I need to add to l liters of pure alcohol to obtain a solution of 45% alcohol? The answer is an EXPRESSION, not an actual answer!! WILL MARK BRAINLIST!!!

Answer 1

Answer: $\dfrac{11}{9}I$

Step-by-step explanation:

Given

There is $l$ liter of pure alcohol

Suppose $x$ liters of water is added

After addition of water, alcohol becomes 45% in concentration

$\Rightarrow \dfrac{l}{x+l}=45\%\\\\\Rightarrow \dfrac{I}{0.45}=x+I\\\\\Rightarrow \dfrac{20}{9}I-I=x\\\\\Rightarrow x=\dfrac{11}{9}I$

Thus,  $\dfrac{11}{9}I$ of water is added to the pure alcohol.