Respuesta :
Answer:
10 liters of the 40% solution, and 10 liters of the 10% solution
Step-by-step explanation:
Let us say that x = the liters of the 40% solution, and y = liters of the 10% solution in her lab. We know that Joy is preparing a solution containing a total 20 liters, so x + y = 20. We can respectively create the following system of equations,
x + y = 20,
0.40x + 0.10y = 0.25 ( 20 )
And now we have to solve this system of equations for x and y, the liters of the 40% solution and the liters of the 10% solution,
[tex]\begin{bmatrix}x+y=20\\ 0.4x+0.1y=0.25\left(20\right)\end{bmatrix}[/tex] ( Substitute x as 20 - y )
[tex]0.4\left(20-y\right)+0.1y=0.25\cdot \:20\end{bmatrix}[/tex] ( Isolate y )
[tex]8-0.3y=5[/tex] ⇒ [tex]80-3y=50[/tex] ⇒ [tex]-3y=-30[/tex] ⇒ y = 10
[tex]x=20-10 = 10[/tex] ⇒ x = 10
Therefore, there are 10 liters of both the 40% and 10% solution.
