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An infinite geometric series has first term \(328\) and a sum of \(2009\). What is its common ratio?

 Jan 6, 2021
 #1
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Sum of an infinite series =    first term / ( 1  -common ratio )

 

2009  =  328/ (1  -r)       rearrange as

 

2009 (1 -r)   = 328

 

2009  - 2009r =  328

 

2009 - 328  =  2009r

 

1681  = 2009 r

 

r   =   1681/2009   = 41/49

 

 

cool cool cool

 Jan 6, 2021

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