$9.$ In the employee scheduling example, suppose that each full$-$time employee works eight hours per day. Thus, Monday's requirement of $17$ employees can be viewed as a requirement of $8(17)=136$ hours. The company can meet its daily labor requirements by using both full$-$time and part$-$time employees. During each week, a full$-$time employee works eight hours per day for five consecutive days, and a part$-$time employee works four hours per day for five consecutive days. A full$-$time employee costs the company $$15$ per hour, whereas a part$-$time employee $($with reduced fringe benefits$)$ costs the company only $$10$ per hour. Company policy limits part$-$time labor to $25\%$ of weekly labor requirements.