Geometric Series and Applications

Which of these formulas represents a geometric sequence?

• 2n = 2,4,6,8,...

• 2ⁿ = 2,4,8,16,...

• n² = 1,4,9,16,...

• 2 + n = 3,4,5,6,...

Find the sum of the infinite geometric series:

200 - 100 + 50 - 25 + ...

• 525 / 2

• 400 / 3

• 3 / 400

• 2 / 525

What is the sum of the first ten terms of the sequence 4, -12, 36, -144 . . . ?

• 59,050

• -59,048

• -78,732

• 118,096

Is the sequence -432, 72, -12, 2,...geometric?

• yes

• no

Find a₁₂ in the sequence -1, -3, -9, -27, ...

• -177,147

• -19,683

• -59,049

• 118,098

Find the 10th term of the following geometric sequence

5, 20, 80, 320, ...

• 81,920

• 327,680

• 1,310,720

• 5,242,880

Find the 7th term in the sequence when the first term is 2, and the common ratio is 4

• 8192

• 32768

• 2048

• 512

List the first five terms of the geometric sequence. Assume that the sequence begins at n = 1.

• 1 , 3 , 6 , 9 , 12

• 3 , 9 , 27 , 81 , 243

• 0 , 1 , 3 , 9 , 27

• 1 , 3 , 9 , 27 , 81

Find the common ratio: 16, 8, 4, 2, ...

• r = 2

• r = 8

• r = 1/4

• r = 1/2

The next term of the sequence 2,4,8,16 is

• 64

• 32

• 108

• 20