Suppose that you are preparing for the upcoming Zombie Apocalypse. The Centers for Disease Control and Prevention recommend that any Zombie Apocalypse Survival Kit should contain at least the following supplies: 

• Water (1 gallon per person per day) 
• Food (stock up on nonperishable items that you eat regularly) 
• Medications (this includes prescription and nonprescription meds) 
• Tools and Supplies (utility knife, duct tape, battery-powered radio, etc.) 
• Sanitation and Hygiene (household bleach, soap, towels, etc.) 
• Clothing and Bedding (a change of clothes for each family member and blankets) 
• Important documents (copies of your driver’s license, passport, and birth certificate, to name a few) 
• First Aid supplies (although you’re a goner if a zombie bites you, you can use these supplies to treat basic cuts and lacerations)

Although not officially recommended by the CDC, your kit should also include at least one self-defense item to protect yourself, your family, and your supplies from zombies and looters. In case of evacuation, each person must be able to carry their survival kit with them. Therefore, your survival kit must not weigh more than 100 lbs. In addition, you must not spend more than $500 on your kit. Your goal is to assemble a kit that maximizes your life expectancy, subject to these weight and cost constraints. Choose reasonable values for the weight and cost of each category of item, and model how each category of item might affect your life expectancy. For example, each gallon of water might increase your life expectancy by 1 day. Then solve the corresponding linear program to determine which supplies you should include in your survival kit.