Geometric Sequences

What is the common ratio of this sequence ? 5, 25, 125, ...

• 4

• 2

• 5

• 6

What is the common ratio of the geometric sequence -1, 6, -36, 216, ...?

• -6

• 6

• 12

• -4

Find the common ratio: 64, -16, 4, -1, ...

• r = -8
• r = -1/4
• r = -4
• r = 4

Solving for the nth term of geometric sequence, given that a₁ = 1 and r= 2, what is the value of the 4th term?

• 2

• 8

• 4

• 16

Write the explicit formula for the geometric sequence.

• a_n = 10(2)^n-1
• a_n = 2(10)^n-1
• a_n = 10(2)ⁿ
• a_n = 2(10)ⁿ

Write the explicit formula for the geometric sequence.

• a_n = 4(3)^n-1
• a_n = 3(4)^n-1
• a_n = -4(3)^n-1
• a_n = 3(-4)^n-1

Find the 9th term in the following geometric sequence:

4, 8, 16, 32, ...

• 384

• 512

• 768

• 1,024

What is the 11th term of the geometric sequence?

• -5120
• 97,656,250
• 19,531,250
• -19,531,250

Given the sequence:

125, 25, 5, ....

Write the rule a_n using the geometric sequence formula:

• a_n = (125)(1/5)^(n-1)

• a_n = 625(1/5)^(n-1)

• a_n = 625(5)^(n-1)

• a_n = 125 + 5n

A geometric sequence has a common ration(r) of 3 and the 8th term (a₈) is 13,122. What is the first term of the sequence (a₁)?

• 3

• 6

• 18

• 2