Question 1091678
80% salt, not possible.
60% salt, not possible.
Dry mixture in some other dry solid granular carrier, yes possible; but solutions in water?  Not possible at those concentrations.


The arithmetic, if ignoring physical reality could go this way:
{{{0.3x+0.8(80-x)=0.6*80}}}, using x for the "ounces" of the 30% salt material.