This is adapted from one of the "Special Mind-Power Exercises" that appear at the end of each chapter of Harry Lorayne's
Ageless Memory: The Memory Expert's Prescription for a Razor-Sharp Mind. (His version used oranges.)
1. SneakySnake just purchased a bagful of new Sony Readers. On her way home, she bumps into poohbear_nc and gives Pooh exactly half her Sonys—plus half a Sony.
2. SneakySnake next meets beppe and gives him exactly half of her remaining Sonys—plus half a Sony.
3. Finally SneakySnake bumps into Latinandgreek, and gives her exactly half of her remaining Sonys—plus half a Sony.
4. By the time she returns home SneakySnake is left with only one Sony, on which she promptly begins reading the latest Dan Brown novel.
Your goal is to figure out how many Sony readers SneakySnake had in the bag at the start.
Show your work!