Expert: Paul Klarreich - 11/18/2010

Question
Hi,

Could you please help me with this?
A beetle starts from point O and walks 0.6m east, then 0.36 m west, 0.216 east and so on. How far does it actually walk?


Answer
Questioner:   toon993
Country:  Bangladesh
Category:  Advanced Math
Private:  No
 
Subject:  Sequences Problem
Question:  Hi,

Could you please help me with this?
A beetle starts from point O and walks 0.6m east, then 0.36 m west, 0.216 east and so on. How far does it actually walk?
........................................
All you really need is a definition of 'and so on.'

Since:
Walk[1] = 0.6^1 = 0.6
Walk[2] = 0.6^2 = 0.36
Walk[3] = 0.6^3 = 0.216
etc.  

It probably means that  Walk[n] = 0.6^n miles, then you have a sum of a geometric sequence, for which you can easily look up the formula.

HOWEVER, if you mean 'how far will it be from O?', that is different.
(but you did not say that)