Miranda and Rob play a game by each tossing a fair coin. The game consists of tossing the two coins together, until for the first time either two heads appear when Miranda wins, or two tails appear when Rob wins.
1) Show that the probability that Miranda wins at or before the nth toss is
2) Show that the probability that the game is decided at or before the nth toss is
Sorry guys, made a bit of a mistake in the question. Should have looked at it better