Solve the following problems dealing with
Arithmetic and Geometric Sequences and Series.
Look carefully at each question to determine with
"which" sequence you are working.
You may wish to have your graphing calculator handy.
1. 

Find the sum of the
first 20 terms of the sequence 4, 6, 8, 10, ...



2. 
Find the sum of
the sequence
8, 5, 2, ..., 7 



3. 
Find the 9^{th} term of the
sequence




4. 

Evaluate this series
using a formula:



5. 
Insert three geometric
means
between 1 and 81. 



6. 
Find a_{6}
for an arithmetic sequence where a_{1 }=
3x+1 and d = 2x+6. 



7. 

Find t_{12}
for a geometric sequence
where t_{1 }=
2 + 2i and r = 3. 


8. 
A display of cans on a grocery shelf consists of 20
cans on the bottom, 18 cans in the next row, and so on
in an arithmetic sequence, until the top row has 4 cans.
How many cans, in total, are in the display?




9. 

How many terms of the arithmetic sequence
3, 2, 7, ... must be added together for the sum of the
series to be 116? 


10. 
Find the indicated sum




11. 

Given the sequence 4, 0, 4, 8, 12, ...,
Darius devises a formula for the sum of n terms of the
sequence. His formula is
Is this formula correct? Show work
to support your answer. 


12. 

Which of the following choices is the formula
for the nth term of the sequence
54, 18, 6, ... ?
Choose:


