Pharmacy

At the pharmacy are in one container 20% solution in the second 50% solution of disinfectant. They need to prepare 4 L of the 48-percent solution.

What amount of solution from each container is needed to mix?

Correct answer:

x =  0.27 L
y =  3.73 L

Step-by-step explanation:

$$\begin{gathered} x+y=4 \\ 0.2x+0.5y=0.48\cdot 4 \\ y=4-x \\ 0.2x+0.5(4-x)=0.48\cdot 4 \\ x=\frac{0.5-0.48}{0.3}\cdot 4=0.27\text{L} \end{gathered}$$

$y=4-x=3.73\text{L}$

Try another example