A walkway lighting package includes a transformer, a certain length of wire, and a certain number of lights on the wire. The price of each lighting package depends on the length of wire and the number of lights on the wire. Use the information below to find the cost of a transformer, the cost per foot of wire, and the cost of a light. Assume that the cost of each item is the same in each lighting package.
• A package that contains a transformer, 25 feet of wire, and 5 lights costs $20.
• A package that contains a transformer, 50 feet of wire, and 15 lights costs $35.
• A package that contains a transformer, 100 feet of wire, and 20 lights costs $50.