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2023 Irish Math Olympiad
P10
P10
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2023 Irish Math Olympiad
Problems
(1)
Number of possible scoreboards
Source: Irish Mathematical Olympiad 2023 Problem 10
5/14/2023
Caitlin and Donal play a game called Basketball Shoot-Out. The game consists of
10
10
10
rounds. In each round, Caitlin and Donal both throw a ball simultaneously at each other's basket. If a player's ball falls into the basket, that player scores one point; otherwise, they score zero points. The scoreboard shows the complete sequence of points scored by each player in each of the
10
10
10
rounds of the game.It turns out that Caitlin has scored at least as many points in total as Donal after every round of the game. Prove the number of possible scoreboards is divisible by
4
4
4
but not by
8
8
8
.
combinatorics