decision variables, objective, constraints, variable restrictions

Formulate, BUT DON'T SOLVE, a mathematical model with linear constraints and a linear objective function for the following story problem. Decision variables should be clearly stated in plain English. A 24-hour supermarket has the following minimal requirements for cashiers: 1 2 3 4 Period Time of day (24-hour clock) Minimum # 1-7 3 7-13 8 13-19 11 19-1 7 Period 1 follows immediately after period 4. Each cashier works 12 consecutive hours, starting at the beginning of one of the four periods. Determine a daily employee worksheet which satisfies the requirements with the least total number of personnel