Re: Sum of a geometric series
[ QUOTE ]
Find the sum (s) of a geometric series for which A1=48, An=3, and r=-1/2
Now, the formula is s = A1/1-r, so 48/1.5 = 32 is what I get.
However, the choices are
– 99, 33, 99, or 15
Why does the formula not use An and should I chose 33 since it is the closest? I am lost.
[/ QUOTE ]
48 + (-24) + 12 + (-6) + 3 = 33.
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