2017 AIME I Problems/Problem 13

Revision as of 16:23, 8 March 2017 by A1b2 (talk | contribs) (Created page with "==Problem 13== For every <math>m \geq 2</math>, let <math>Q(m)</math> be the least positive integer with the following property: For every <math>n \geq Q(m)</math>, there is a...")
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Problem 13

For every $m \geq 2$, let $Q(m)$ be the least positive integer with the following property: For every $n \geq Q(m)$, there is always a perfect cube $k^3$ in the range $n < k^3 \leq m \cdot n$. Find the remainder when \[\sum_{m = 2}^{2017} Q(m)\]is divided by 1000.

Solution

Lemma: The ratios between $k^3$ and $(k+1)^3$ decreases as $k$ increases.