Understanding and applying geometric series

Find the sum of the first 16 terms of the geometric sequence:

20 + 4 + 4/5 + ...

• 25

• 19.8

• 7.6 x 10^11

• 344

Evaluate (that is, find the sum) the geometric series below:

4, - 8 , 16 - 32..., n = 7

• 195

• 518

• 516

• 145

Find the indicated sum for the geometric series.

S₆ for (-4/5) + 8 + (-80) + 800 + ....

• _S6 = 21,845

• _S6 = 72,000

• S6 = $\frac{363636}{5}$

• S6 = $\frac{-644204}{5}$

The sum of an finite Geometric series is given by:

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• 
• 
• 

Evaluate the geometric series described.
 $3+15+75+375...,\ \ \ \ n=6$  

• 11,718

• 10,603

• 9,769

•  $-\frac{3}{4}$  

 $a_1=-2,\ \ \ r=-2,\ \ \ S_n=22$  Determine the number of terms n in the series

• 6

• 7

• 8

• 5

• 11.74
• 13.32
• 29.97
• 39.96

The first day the magazine was published the company got 190 responses but they were declining by 10% each day assuming this continues, how many total responses would the company get over the first 29 days?

• $S_n=\frac{190-190\left(.90\right)^{29}}{1-.90}$

• $S_n=\frac{190-190\left(.10\right)^{29}}{1-.10}$

• $S_n=\frac{190-190\left(1.10\right)^{29}}{1-1.10}$

• $a_n=190\left(.90\right)^{n-1}$

Evaluate the sum of the geometric series:

-1 + 5 - 25 + 125 + ... + 78,125

• 65104

• 56732

• -1/6

• 65816

Evaluate the geometric series below:
a₁ = 4, a_n = 262144, r = 4

• 349524
• 341690
• 344023
• 338135