2021 USAJMO Problems/Problem 5
A finite set 
of positive integers has the property that, for each 
and each positive integer divisor 
of 
, there exists a unique element 
satisfying 
. (The elements and 
could be equal.)
Given this information, find all possible values for the number of elements of .
Solution
See Also
| 2021 USAJMO (Problems • Resources) | ||
| Preceded by Problem 3 |
Followed by Problem 5 | |
| 1 • 2 • 3 • 4 • 5 • 6 | ||
| All USAJMO Problems and Solutions | ||
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