Difference between revisions of "2021 AIME II Problems/Problem 8"

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==Solution==
 
==Solution==
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This problem needs a chart, so we'll need to draw a table.
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PLEASE DO NOT EDIT WHILE I AM WORKING ON THIS PROBLEM. THANK YOU ~ arcTICTURN
  
 
==See also==
 
==See also==
 
{{AIME box|year=2021|n=II|num-b=7|num-a=9}}
 
{{AIME box|year=2021|n=II|num-b=7|num-a=9}}
 
{{MAA Notice}}
 
{{MAA Notice}}

Revision as of 20:18, 22 March 2021

Problem

An ant makes a sequence of moves on a cube where a move consists of walking from one vertex to an adjacent vertex along an edge of the cube. Initially the ant is at a vertex of the bottom face of the cube and chooses one of the three adjacent vertices to move to as its first move. For all moves after the first move, the ant does not return to its previous vertex, but chooses to move to one of the other two adjacent vertices. All choices are selected at random so that each of the possible moves is equally likely. The probability that after exactly 8 moves that ant is at a vertex of the top face on the cube is $\frac{m}{n}$, where $m$ and $n$ are relatively prime positive integers. Find $m + n.$

Solution

This problem needs a chart, so we'll need to draw a table.

PLEASE DO NOT EDIT WHILE I AM WORKING ON THIS PROBLEM. THANK YOU ~ arcTICTURN

See also

2021 AIME II (ProblemsAnswer KeyResources)
Preceded by
Problem 7
Followed by
Problem 9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
All AIME Problems and Solutions

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