You and I play a game involving successive throws of a fair coin.
Suppose I pick HH and you pick TH. The coin is thrown repeatedly
until we see either two heads in a row (I win) or a tail followed
by a head (you win). What is the probability that you win?
The Better Bet
Age 14 to 16 Challenge Level:
Which of the following is the better bet, if both games cost £1 to play?
Getting two heads and two tails on four coins wins you £3
You win £2 for every six that appears when three standard dice are rolled
You may wish to explore this using the interactive environment below.
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice.