Answer:
6 L
Step-by-step explanation:
Given two solutions:
1st solution is 90% saline solution. Let the volume of this solution be [tex]x[/tex] litres.
2nd solution is 50% saline solution. Volume of this solution = 4 L
Resultant solution is 74% saline.
To find:
The volume of 1st solution = ?
Solution:
Total volume of the 74% saline mixture = (4+[tex]x[/tex]) Litres
We can write equation here, as per the percentage of saline in the mixtures.
90% of [tex]x[/tex] L + 50% of 4 L = 74% of ([tex]x[/tex]+4)
[tex]\Rightarrow \dfrac{90x}{100} + \dfrac{50}{100}\times 4 = \dfrac{74}{100}\times (x+4)\\\Rightarrow 90x + 200 = 74x+296\\\Rightarrow 90x-74x = 296-200\\\Rightarrow 16x = 96\\\Rightarrow x = \bold{6\ L}[/tex]
Therefore, the volume must be 6 L.
