You have a 50% chance of winning a game. If you play the game twice, what is the probability that you will win at least once?
The probability of winning at least once is 75%.

Here's the reasoning behind this:

1. There are four possible outcomes when playing the game twice: Win-Win, Win-Lose, Lose-Win, and Lose-Lose.
2. Each outcome has a probability of 0.5 * 0.5 = 0.25 (or 25%) since there's a 50% chance of winning each game.
3. To find the probability of winning at least once, we can either add up the probabilities of the outcomes where you win at least one game (Win-Win, Win-Lose, and Lose-Win) or subtract the probability of the outcome where you don't win any games (Lose-Lose) from 100%.
4. Adding up the probabilities of the three favorable outcomes: 0.25 + 0.25 + 0.25 = 0.75 (or 75%).
5. Alternatively, subtracting the probability of not winning any games from 100%: 1 - 0.25 = 0.75 (or 75%).

So, the probability of winning at least once when playing the game twice is 75%.