Difference between revisions of "2017 IMO Problems/Problem 5"

 
(2 intermediate revisions by 2 users not shown)
Line 1: Line 1:
 +
==Problem==
 +
 
An integer <math>N \ge 2</math> is given. A collection of <math>N(N + 1)</math> soccer players, no two of whom are of the same height, stand in a row. Sir Alex wants to remove <math>N(N - 1)</math> players from this row leaving a new row of <math>2N</math> players in which the following <math>N</math> conditions hold:
 
An integer <math>N \ge 2</math> is given. A collection of <math>N(N + 1)</math> soccer players, no two of whom are of the same height, stand in a row. Sir Alex wants to remove <math>N(N - 1)</math> players from this row leaving a new row of <math>2N</math> players in which the following <math>N</math> conditions hold:
  
Line 10: Line 12:
  
 
Show that this is always possible.
 
Show that this is always possible.
 +
 +
==Solution==
 +
{{solution}}
 +
 +
==See Also==
 +
 +
{{IMO box|year=2017|num-b=4|num-a=6}}

Latest revision as of 01:42, 19 November 2023

Problem

An integer $N \ge 2$ is given. A collection of $N(N + 1)$ soccer players, no two of whom are of the same height, stand in a row. Sir Alex wants to remove $N(N - 1)$ players from this row leaving a new row of $2N$ players in which the following $N$ conditions hold:

($1$) no one stands between the two tallest players,

($2$) no one stands between the third and fourth tallest players,

$\;\;\vdots$

($N$) no one stands between the two shortest players.

Show that this is always possible.

Solution

This problem needs a solution. If you have a solution for it, please help us out by adding it.

See Also

2017 IMO (Problems) • Resources
Preceded by
Problem 4
1 2 3 4 5 6 Followed by
Problem 6
All IMO Problems and Solutions