Jones installs and demonstrates smoke detectors. There are two types of smoke detectors, type A and Type B. Type A requires 1 hour to install and...

Ms. Jones installs and demonstrates smoke detectors. There are two types of smoke detectors, type A and Type B. Type A requires 1 hour to install and 1/3 hour to demonstrate. Type B requires 1.5 hours to install and 1/5 hour to demonstrate. Company rules require Ms. Jones to work a minimum of 20 hours as an installer and a maximum of 15 hours a week as a demonstrator. She earns $8 per hour as an installer and $5 per hour as a demonstrator. How many of each type of alarm should she install and demonstrate to maximize her income?