.
The maximal salt concentration in water is 28%.
https://en.wikipedia.org/wiki/Saline_water
The rest is your fantasy (or fantasy your teacher, who does not know Science).
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Comment from student: The fact that the word water appears anywhere in the question is your fantasy.
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My response : Your comment/reaction is INCORRECT.
Your correct comment/reaction would be "Thanks for opening my eyes on the relevant facts I was not familiar with".
And had you comment in this way, I'd tell you that this linear theory DOESN'T WORK AT ALL
for high-concentrated mixtures of salts in liquids.
It works for low-concentrated salts mixtures in liquids, O-N-L-Y.
Let me repeat it one more time : your reaction goes across your interests.
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Alan, on your comment
"There's no reason to assume it's in NaCl in water"
I have good answer:
But there is nothing in the problem that prohibits me to make this assumption . . . "
I always become very angry when see such "problems".
Their creators do not know subject at all, and all what they do is spreading FAKES in the Internet, instead of spreading knowledge.