Join the USAMO Guide Discord Server. Regular updates are posted there!

Let me Join!
Dismiss

Harvard-MIT Mathematics Tournament #0i9g

Harvard-MIT Mathematics TournamentHard

From module Sequences and Series II

Community difficultyNo ratings yetBe the first to rate this problem.
Understand the scale
Scale 0.5: Easiest math competition problems, often solvable even for early middle school students without experience. 1: Problems strictly for beginners, often at a moderate middle school level. 1.5: Problems for stronger beginner students, on the level of the middling problems in most middle school contests. 2: For motivated beginners, harder questions from the previous categories. 2.5: More advanced beginner problems, hardest questions from previous categories. 3: Early intermediate problems that require more creative thinking. 3.5: Tougher early intermediate problems that consistently stretch into higher-level creative thinking or conceptual knowledge. 4: Intermediate-level problems. 4.5: Upper intermediate problems approaching the upper bound for non-invitational sprint math competitions. 5: More difficult AIME problems or simple proof-based Olympiad-style problems. 6: High-level AIME-styled questions or introductory Olympiad-level questions. 7: Tougher Olympiad-level questions, may require more technical knowledge. 8: High-level Olympiad-level questions. 9: Expert Olympiad-level questions. 9.5: The hardest problems appearing on Olympiads which the strongest students could reasonably solve. 10: Historically notorious problems, generally unsuitable for even very hard competitions because they are exceedingly tedious, long, and difficult.
Sequences and Series

Problem

Problem:

The sequence of real numbers x1,x2,x3,…x_{1}, x_{2}, x_{3}, \ldots satisfies lim⁡n→∞(x2n+x2n+1)=315\lim_{n \rightarrow \infty}\left(x_{2 n}+x_{2 n+1}\right)=315 and lim⁡n→∞(x2n+x2n−1)=2003\lim_{n \rightarrow \infty}\left(x_{2 n}+x_{2 n-1}\right)=2003. Evaluate lim⁡n→∞(x2n/x2n+1)\lim_{n \rightarrow \infty}\left(x_{2 n} / x_{2 n+1}\right).

← Back to all problems