Suppose they make deluxe notebooks and regular notebooks.
The total selling price is $ .
a deluxe notebook with subject dividers, which sells for $4.00, and a regular notebook, which sells for $3.00.
So the total production cost is $
The production cost is $3.20 for each deluxe notebook, and $2.60 for each regular notebook
between 2000 and 3000 deluxe notebooks
between 3000 and 6000 regular notebooks
not more than 7000 altogether
Can you continue from here?