Let the manufacturer produce x packages of nuts and y packages of bolts. Therefore, x ≥ 0 and y ≥ 0
The given information can be compiled in a table as follows.

The profit on a package of nuts is Rs 17.50 and on a package of bolts is Rs 7. Therefore, the constraints are
x+3y≤12
3x+y≤12
Total profit, Z = 17.5x + 7y
The mathematical formulation of the given problem is Maximise Z = 17.5x + 7y … (1) subject to the constraints, x + 3y ≤ 12 … (2) 3x + y ≤ 12 … (3) x, y ≥ 0 … (4)
The feasible region determined by the system of constraints is as follows.

The corner points are A (4, 0), B (3, 3), and C (0, 4).
The values of Z at these corner points are as follows.

The maximum value of Z is Rs 73.50 at (3, 3). Thus, 3 packages of nuts and 3 packages of bolts should be produced each day to get the maximum profit of Rs 73.50.