MathDB
2023 Fall LMT Speed p16 , number in base 10,11,12

Source:

March 2, 2024
number theory

Problem Statement

Jeff writes down the two-digit base-1010 prime ab10‾\overline{ab_{10}}. He realizes that if he misinterprets the number as the base 1111 number ab11‾\overline{ab_{11}} or the base 1212 number ab12‾\overline{ab_{12}}, it is still a prime. What is the least possible value of Jeff’s number (in base 1010)?
Proposed byMuztaba Syed
Back to ProblemsView on AoPS