2020 IMO Problems/Problem 5: Difference between revisions
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For which <math>n</math> does it follow that the numbers on the cards are all equal? | For which <math>n</math> does it follow that the numbers on the cards are all equal? | ||
==Solution 1== | |||
== Video solution == | == Video solution == | ||
Revision as of 22:04, 12 August 2025
Problem
A deck of
cards is given. A positive integer is written on each card. The deck has the property that the arithmetic mean of the numbers on each pair of cards is also the geometric mean of the numbers on some collection of one or more cards.
For which
does it follow that the numbers on the cards are all equal?
Solution 1
Video solution
https://www.youtube.com/watch?v=dTqwOoSfaAA [video covers all day 2 problems]
See Also
| 2020 IMO (Problems) • Resources | ||
| Preceded by Problem 4 |
1 • 2 • 3 • 4 • 5 • 6 | Followed by Problem 6 |
| All IMO Problems and Solutions | ||