Problem B. 4678. (January 2015)
B. 4678. Ann and Bill take turns writing digits on a sheet of paper, left to right. Ann starts with a nonzero digit, and they continue until a 100-digit number is formed. Bill wins if the resulting number divided by 11 leaves a remainder of 5, otherwise Ann wins. Both players are good at mathematics. Who will win the game?
Suggested by Gy. Károlyi, Budajenő
Deadline expired on February 10, 2015.
176 students sent a solution. 4 points: 85 students. 3 points: 42 students. 2 points: 26 students. 1 point: 21 students. 0 point: 2 students.