Difference between revisions of "2006 AMC 12B Problems/Problem 25"

(Solution)
(Problem)
Line 2: Line 2:
 
{{empty}}
 
{{empty}}
 
== Problem ==
 
== Problem ==
{{problem}}
+
A sequence <math>a_1,a_2,\dots</math> of non-negative integers is defined by the rule <math>a_{n+2}=|a_{n+1}-a_n|</math> for <math>n\geq 1</math>. If <math>a_1=999</math>, <math>a_2<999</math> and <math>a_{2006}=1</math>, how many different values of <math>a_2</math> are possible?
 +
 
 +
<math>
 +
\mathrm{(A)}\ 165
 +
\qquad
 +
\mathrm{(B)}\ 324
 +
\qquad
 +
\mathrm{(C)}\ 495
 +
\qquad
 +
\mathrm{(D)}\ 499
 +
\qquad
 +
\mathrm{(E)}\ 660
 +
</math>
  
 
== Solution ==
 
== Solution ==

Revision as of 01:10, 4 February 2010

This is an empty template page which needs to be filled. You can help us out by finding the needed content and editing it in. Thanks.

Problem

A sequence $a_1,a_2,\dots$ of non-negative integers is defined by the rule $a_{n+2}=|a_{n+1}-a_n|$ for $n\geq 1$. If $a_1=999$, $a_2<999$ and $a_{2006}=1$, how many different values of $a_2$ are possible?

$\mathrm{(A)}\ 165 \qquad \mathrm{(B)}\ 324 \qquad \mathrm{(C)}\ 495 \qquad \mathrm{(D)}\ 499 \qquad \mathrm{(E)}\ 660$

Solution

http://www.unl.edu/amc/mathclub/5-0,problems/H-problems/H-pdfs/2006/HB2006-25.pdf

See also

2006 AMC 12B (ProblemsAnswer KeyResources)
Preceded by
Problem 24
Followed by
Last Question
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions