MathDB
Floor of cube roots

Source: AIME II 2007 #7

March 29, 2007
geometry3D geometryfloor functioncalculusintegrationAMC

Problem Statement

Given a real number x,x, let x\lfloor x \rfloor denote the greatest integer less than or equal to x.x. For a certain integer k,k, there are exactly 7070 positive integers n1,n2,,n70n_{1}, n_{2}, \ldots, n_{70} such that k=n13=n23==n703k=\lfloor\sqrt[3]{n_{1}}\rfloor = \lfloor\sqrt[3]{n_{2}}\rfloor = \cdots = \lfloor\sqrt[3]{n_{70}}\rfloor and kk divides nin_{i} for all ii such that 1i70.1 \leq i \leq 70. Find the maximum value of nik\frac{n_{i}}{k} for 1i70.1\leq i \leq 70.