Answer:
The answer is 4 liters.
Step-by-step explanation:
We want a final 25% solution, which means that the solvent should constitute 25 percent of all the liters of solution.
Let us call the litres of 40% solution, so when they are added to the 12 litres of 20% solution, the total litres of the new solution are:
of these liters, 25% must be the solvent:
Now for the 40% solution, the liters of the solvent are , and for the 20% liter solution, the liters of solve are liters. Thus the total liters of the solvent are
Therefore
When there is a midpoint in a line segment, the two segments that are then produced have to be equal. So that means that because E is a midpoint of DF, DE=EF.
Set up the equation.
DE=EF
2x+4=3x+1
Then solve for x.
x=3
Then plug it back in the equation to find DE and EF.
DE=2x+4=2(3)+4=10
Because DE=EF then EF is also 10.
DF is made from the addition of DE and EF so DF is twice EF.
DF= 20
DE= 10, EF= 10, DF= 20
Hope this helps.
Answer:
pretty sure it's D........