Ch2, Problem 40: Formulation Write down the formulation in the answer box below. Make sure the following four components are included: Variable definitions: Use a separate line for variable;Start each variable definition with "Let"; Example: Let x1 denote ... Specify the units. Example: number of bags, gallons of a liquid, pounds (lbs) of flours, etc. An objective function: Start with either "max Z=" or "min Z="; Include only linear terms of decision variables after ``=". A set of constraints: Start with "s.t." for the 1st constraint; Left-hand-side (LHS) of each constraint should only include linear terms of decision variables;Right-hand-side (RHS) of each constraint should only have numbers;Do not include ``s.t." for other constraints. A set of variable restrictions: Start with "and";Group variable restrictions if they are all non-negatively restricted.