Posted by **alix** on Tuesday, June 15, 2010 at 9:16pm.

If the seventh term of a geometric series is 192, and the first term is 3, find the sum of the first 8 terms of the series

- math B30 -
**Reiny**, Tuesday, June 15, 2010 at 9:49pm
ar^6 = 192 , a=3

r^6 = 192/3 = 64

r = 2

sum(8) =a(r^8 - 1)/(r-1)

= 3(256-1)/(2-1) = 765

- math B30 -
**alix**, Tuesday, June 15, 2010 at 10:04pm
i dont understand how you get r?

- math B30 -
**alix**, Tuesday, June 15, 2010 at 10:07pm
nvm i got i thank you so much

- math B30 -
**Common difference**, Monday, July 7, 2014 at 6:39am
Mathe matics

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