Track / Stage 2 / 19 of 240 #259 of 2444
Problem 259 Number theory Difficulty 2.2 Multiple choice CEMC Fermat · Canada · 2025
The current calendar year, 2025 2025 2025 , is a perfect square. In n n n years from 2025, the calendar year will again be a perfect square. The smallest possible value of n n n is
Pick one
A 2025 2025 2025 B 100 100 100 C 9 9 9 D 46 46 46 E 91 91 91
Show the answer
Next problem →
Official solutions — 2 Solution 1 Since 2025 = 45 \sqrt{2025}=45 2025 = 45 , the next largest perfect square greater than 2025 is 46 2 = 2116 46^2=2116 4 6 2 = 2116 .
Thus, the smallest possible value of n n n is 2116 − 2025 = 91 2116-2025=91 2116 − 2025 = 91 .
Solution 2 Since 2025 = 45 \sqrt{2025}=45 2025 = 45 , the next largest perfect square greater than 2025 is 46 2 = 2116 46^2=2116 4 6 2 = 2116 .
Thus, the smallest possible value of n n n is 2116 − 2025 = 91 2116-2025=91 2116 − 2025 = 91 .
← Previous All problems Next →
Source: CEMC, University of Waterloo ,
licensed CC-BY-NC-4.0 .
Statement reproduced verbatim; metadata (topic, difficulty, ordering) added by this project.