MathDB
the equation is satisfied for infinitely many positive integers n

Source: CAPS Match 2023 P4

August 18, 2023
floor function

Problem Statement

Let p,qp, q and rr be positive real numbers such that the equation pn+qn+rn=n\lfloor pn \rfloor + \lfloor qn \rfloor + \lfloor rn \rfloor = n is satisfied for infinitely many positive integers nn{}. (a) Prove that p,qp, q and rr are rational. (b) Determine the number of positive integers cc such that there exist positive integers aa and bb, for which the equation na+nb+cn202=n\left \lfloor \frac{n}{a} \right \rfloor+\left \lfloor \frac{n}{b} \right \rfloor+\left \lfloor \frac{cn}{202} \right \rfloor=n is satisfied for infinitely many positive integers nn{}.