The remainder of 1+2+...+k
Source: Korea National Olympiad 2010 Problem 8
September 9, 2012
modular arithmeticnumber theory proposednumber theory
Problem Statement
There are people sitting around a round table. First, we give one person a candy. Next, we give candies to st person, th person, th person, , and th person clockwise from . Find the number of people who get at least one candy.