Case One A large multinational grocery chain that emphasizes healthy lifestyles is recognized as one of the nation's "greenest" companies and is perennially rated as one of the best places to work. Full$-$time and longer$-$service part$-$time staff receive health insurance coverage. Most employees receive a $20$ percent discount on company products. Employees who participate in the company's voluntary "Healthy Discount Incentive Program" receive up to another $10$ percent discount on their purchases $($i$.$e$.,$ up to a total $30$ percent discount$).$ These additional discounts are calculated from employees' blood pressure, total cholesterol $($or LDL$)$ levels, Body Mass Index $($BMI$),$ and nicotine$-$free lifestyle. For example, the full additional $10$ percent discount is awarded to those who do not use $72$