AoPSWiki
Want to learn how to tackle those tough AMC/AIME/Olympiad algebra problems? Check out Art of Problem Solving's Intermediate Algebra by Richard Rusczyk and Mathew Crawford. Over 1600 problems!

2007 Alabama ARML TST Problems/Problem 7

From AoPSWiki

Problem

Find the number of distinct integers in the list

\left\lfloor \dfrac{1^2}{2007}\right\rfloor , \left\lfloor \dfrac{2^2}{2007}\right\rfloor , \left\lfloor \dfrac{3^2}{2007}\ri...

where \lfloor x \rfloor represents the greatest integer less than or equal to x.

Solution

The first time that the difference of two consecutive squares is greater than or equal to 2007 is 1004^2-1003^2=2007. Below \left\lfloor \frac{1003^2}{2007}\right\rfloor =501, every non-negative integer can be reached. Then above that, each number is distinct. So there are 502+(2007-1004+1)=\boxed{1506} distinct integers in the given list.

See also

2007 Alabama ARML TST (Problems)
Preceded by:
Problem 6
Followed by:
Problem 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Do you have what it takes to be the next brilliant trader, researcher, or developer at Jane Street Capital? Find out in the Careers in Mathematics Forum.
© Copyright 2008 AoPS Incorporated. All Rights Reserved. • FoundationPrivacyContact Us