Arithmetic and Geometric Sequences

Is the sequence arithmetic, geometric or neither?

• Arithmetic

• Geometric

• Neither

Is the sequence arithmetic, geometric or neither?

• Arithmetic

• Geometric

• Neither

Is the sequence arithmetic, geometric or neither?

• Arithmetic

• Geometric

• Neither

Is the sequence arithmetic, geometric or neither?

• Arithmetic

• Geometric

• Neither

Find  $a_{21}$  given the sequence 10, 6, 2, -2, ...

• -74

• -70

• 70

• 90

Find  $a_5$  if  $a_1=40$  and  $r=\frac{1}{2}$  .

• 160000

•  $\frac{5}{4}$  

•  $\frac{5}{2}$  

• 5

Find $a_{12}$ given the sequence 7, 21, 63, 189, ... 

• 413343

• 3720087

•  $5.93\ \times10^9$  

• 1240029

Find $a_{90}\ if\ a_1=8\ and\ d=-4$ 

• -348

• -352

• 364

• 368

In 2001, a radio station had a contest in which listeners had a chance to win $1000 every hour. The contest started at $1000, and $97 was added for the next caller each time the previous caller answered the question incorrectly. How much money would you win if you were the 18th caller and the first person to answer the question correctly?

• $2728

• $2649

• $2746

• $2552

On your first birthday, your grandmother deposits $0.25 into a savings account for you. On each birthday after that, she says she will deposit double the amount she put in the year before. How much money does she deposit on your 25th birthday?

• $4,194,304

• $8,388,608

• $2,097,152

• $48.25