A smartphone battery lasts for hours if it is left on but not actively used. If it is used constantly, the battery lasts for only hours. Since its last full charge, the phone has been on for hours, and during that time it was actively used for minutes. If the user stops actively using the phone but leaves it on, how many more hours will the battery last?
8.5
9.5
10.5
11.5
12.5
