Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2021 — Part 02 Question 23

Math Olympiad Vault · MathNet 2021 — Part 02

Question 23

Anne, Ellie and Milo play a game on a hexagonal board tiled with hexagons, $n \gt 2$ hexagons on each side. The game begins with a token on a tile in one of corner of the board. Ellie and Milo are on the same team, playing against Anne, and they win if the token lands on center of the board. Anne, Ellie and Milo take turns moving the token, Anne begins, then Ellie and then Milo.
The turns proceed as follows:
* Anne has to move the token to an adjacent hexagon, in any direction.
* Ellie has to move the token by two hexagons in any of the 6 possible directions.
* Milo has a choice of passing the turn, or moving the token by three hexagons in any of the 6 possible directions.
Find all $n \gt 2$ for which Ellie and Milo have a winning strategy.

Question illustration
Figure 1: A board with 5 hexagons on each side.