12. Andrea and Chiara are challenging each other by rolling a die multiple times. Every time an odd number comes up, Andrea scores a point; when an even number comes up, Chiara scores a point. The game is won by the first to reach 5 points. After 6 rolls, Andrea is leading 4 to 2. What is the probability that Chiara will win the game?
(A) $1 / 8$
(B) $1 / 3$
(C) $1 / 6$
(D) $1 / 4$
(E) $1 / 5$
(12) The correct answer is $(A)$.

Chiara wins the game only if she scores a point with all three consecutive throws. Since the throws are independent events, her probability of winning is $(1 / 2)^{3}=1 / 8$.

Problem proposed by Carmelo Di Stefano.