dave and ellen are newly married and living in their first house. the yearly premium on their homeowner’s insurance policy is $250 for the coverage they need. their insurance company offers an annual discount of 5 percent if they install dead-bolt locks on all exterior doors. the couple can also receive an annual discount of 2 percent if they install smoke detectors on each floor. they have contacted a locksmith, who will provide and install dead-bolt locks on the two exterior doors for $45 each. at the local hardware store, smoke detectors cost $4 each, and the new house has two floors. dave and ellen can install the smoke detectors themselves.
