Isabella is playing American roulette, where there are 38 spaces on a wheel, and there is a ball that is equally likely to land in each space. She plays 5 times, and the spins of the wheel are independent. If it lands in any of the 18 red spaces Isabella wins $1, but otherwise she loses $1. After her 5 plays, what is the probability that she ends up with more money than when she started?
[Author Mark Huber. Licensed under Creative Commons]
