Maths Olympiad Prep

Library / /358 of 387

, 2006

Combinatorics Difficulty 3.0 AMC 10/12 Find the answer Canada

Anne and Brenda play a game which begins with a pile of nn toothpicks. They alternate turns with Anne going first. On each player's turn, she must remove 11, 33 or 44 toothpicks from the pile. The player who removes the last toothpick wins the game. For which of the following values of nn does Brenda have a winning strategy? (In a game, a player has a winning strategy if, regardless of what the other player does, there are moves that she can make which guarantee that she will win.)

(A) 3131 (B) 3232 (C) 3333 (D) 3434 (E) 3535

Want a route through all this instead of an archive? The track puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.