Baltic Way 1993 · Problem 1
Number Theory
and are two three-digit decimal numbers, with being different non-zero digits. The squares of these numbers are five-digit numbers and respectively. Find all such threedigit numbers.
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Review
Topics
Divisibility and factorization
Solutions
Solution
Solution:
Assume . As the square of must be a five-digit number we have . Now a straightforward case study shows that can be 301, 311, 201, 211 or 221.
Contest context
Results from Baltic Way 1993
8 teams
- Mean score
- 4.4 / 5
- Scores of 4 or 5
- 7 / 8
- Estonia
- 5 / 5
Score distribution
00
10
20
31
43
54
All team scores
| Team | Score |
|---|---|
| Poland | 5 / 5 |
| Latvia | 4 / 5 |
| Estonia | 5 / 5 |
| Sweden | 4 / 5 |
| Lithuania | 5 / 5 |
| Finland | 3 / 5 |
| Iceland | 5 / 5 |
| Denmark | 4 / 5 |