Q18: Degree of the objective function of an LPP

A linear programming problem optimises a linear function $Z = ax + by$ subject to linear constraints. Linear means each variable appears only to the power 1, with no products such as $xy$ and no powers such as $x^2$⁠.

The degree of a polynomial is the highest power among its terms. Both $ax$ and $by$ have power 1.

Watch out: degree 0 would make $Z$ a constant, with nothing to optimise. Degree 2 or more needs terms such as $x^2$ or $xy$⁠, and then the problem is no longer linear.