Problem C. 1304. (September 2015)

C. 1304. Two players are playing the following game: They take turns in writing a natural number 1 to 10 on a blackboard. It is only allowed to write a number that does not divide any of the numbers written on the board previously. If a player is not able to write a new number on the board, he loses the game. Show that the starting player has a winning strategy.

(5 pont)

Deadline expired on October 12, 2015.

Statistics:

221 students sent a solution.
5 points:	80 students.
4 points:	19 students.
3 points:	10 students.
2 points:	9 students.
1 point:	56 students.
0 point:	45 students.
Unfair, not evaluated:	2 solutionss.

Problems in Mathematics of KöMaL, September 2015