AMC12 Sequences and Series

Question 1

What is the 10th term of the arithmetic sequence 3, 7, 11, 15, ...?

Accepted Answer

39

Answer

43

Answer

35

Answer

47

Question 2

What is the sum of the first 100 positive integers?

Accepted Answer

5050

Answer

5000

Answer

4950

Answer

10100

Question 3

A geometric sequence has first term 2 and common ratio 3. What is the 5th term?

Accepted Answer

162

Answer

486

Answer

54

Answer

243

Question 4

What is the sum of the infinite geometric series 1 + 1/2 + 1/4 + 1/8 + ...?

Accepted Answer

2

Answer

4

Answer

1

Answer

3/2

Question 5

In the Fibonacci sequence 1, 1, 2, 3, 5, 8, ..., what is the 8th term?

Accepted Answer

21

Answer

13

Answer

34

Answer

18

Question 6

The sum of the first n terms is Sₙ = 2n² + 3n. What is the first term a₁?

Accepted Answer

5

Answer

2

Answer

3

Answer

7