Geometric Sequences and Series

Find the common ratio for the geometric sequence.

• 10
• 1/2
• 2
• 4

Find the common ratio for the geometric sequence.

• -4
• 4
• 1/4
• -1/4

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

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

• 64
• 32
• 108
• 20

Find the first four terms of the sequence given the rule:
a_n = 4(5)^n-1

• 20, 100, 500, 2500
• 5, 20, 80, 320
• 4, 20, 100, 500
• 4, 9, 14, 19

Is the sequence-4, -12, -36, -108,... geometric?

• yes
• no

What is the 11th term of the geometric sequence?

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

What is the 11th term of the geometric sequence?

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

• -28,056

• -29,523

• -31,724

• -30,628

What is the sum of the first 9 terms of the geometric sequence:

{1,3,9,...,n}

• 9841

• 105467

• 29523

• 6566