Rita and Sam play the following game with n sticks on a table. Each must remove 1, 2, 3, 4 or 5 sticks at a time on altemate tums, and no stick that is removed is put back on the table.The one who removes the last stick(or sticks) from the table wins. If Rita goes first, which of the following is a value of n such that Sam can always win no matter how Rita plays?
7
10
11
12
16
针对此类问题,抓住一个核心,无论Rita先拿走几根木棍,Sam总能够使第一个来回两人拿走的木棍总数为6,举个栗子,如果Rita先拿走1个,Sam就拿走5个,如果Rita拿走5个,Sam就拿走1个。所以,选项中是6的倍数的是正确选项,无论Rita怎么拿,Sam都会赢
登录 或 注册 后可以参加讨论