MathDB

Set of integers

Source: APMO 2001

March 19, 2006

number theorycountingfloor function

Problem Statement

Find the largest positive integer

N

so that the number of integers in the set

\{1,2,\dots,N\}

which are divisible by 3 is equal to the number of integers which are divisible by 5 or 7 (or both).