Thread: homework due tomorrow.

Solution A is 30% alcohol and solution B is 60% alcohol. How much of each is needed to make 80 liters of a solution that is 45% alcohol?

please help.

Originally Posted by heather_meaghan

Solution A is 30% alcohol and solution B is 60% alcohol. How much of each is needed to make 80 liters of a solution that is 45% alcohol?

please help.

Call the amount of each solution needed $\displaystyle x$ and $\displaystyle y$ (measured in liters). We know that if we combine these two amounts, we should get a total of 80 liters, so

$\displaystyle x + y = 80$.

We also know that we want our final solution to be 45% alcohol, so

$\displaystyle 0.30x + 0.60y = 0.45\cdot80$.

Solve for $\displaystyle x$ and $\displaystyle y$.

thank you very much.