Answer:
We have to add 1.86 L of water to make the solution 7% saline.
Step-by-step explanation:
The concentration of a saline solution is given by
C(x) = [tex]\frac{0.2}{1+x}[/tex]
where x represents the amount of water used to dilute the solution.
We have to find how much water must be added to obtain a solution that is 7% saline.
If we see the equation we notice that as we add the value of x, the concentration of the solution decreases.
Here C(x) = 0.07
0.07 = [tex]\frac{0.2}{1+x}[/tex]
Rearranging,
1 + x = [tex]\frac{0.2}{0.07}[/tex]
1 + x = 2.86
x = 1.86 L
We have to add 1.86 L of water to make the solution 7% saline.
