Imagine a coin-tossing bet game. You pay \$1 to play the game (for one toss), and if you win you get a prize of \$3. The \$1 to play is not refunded. The probability of winning and losing is equal. If you play the game 100 times, what's the probability that you will have more money than when you started?
I have worked out that the expected value after playing a game is \$1(gaining a dollar per game). Based on this, I couldn't quite figure out the answer to the probability question.
Please explain your answer.