NBT NBT Mathematics: Sequences, Series and Patterns 1

Question 1

The first three terms of an arithmetic sequence are 5, 11, 17. What is the 20th term?

Accepted Answer

119

Answer

121

Answer

123

Answer

125

Question 2

A geometric sequence has first term 4 and common ratio 3. What is the 5th term?

Accepted Answer

324

Answer

108

Answer

243

Answer

972

Question 3

What is the sum of the first 10 terms of the arithmetic series 3 + 7 + 11 + …?

Accepted Answer

210

Answer

183

Answer

220

Answer

230

Question 4

Which formula gives the nth term of the sequence 2, 5, 10, 17, 26, …?

Accepted Answer

Tₙ = n² + 1

Answer

Tₙ = 2n + 1

Answer

Tₙ = n² − 1

Answer

Tₙ = 3n − 1

Question 5

The sum of an infinite geometric series is 40 and its first term is 10. What is the common ratio?

Accepted Answer

0.75

Answer

0.25

Answer

0.50

Answer

0.60

Question 6

A sequence is defined recursively as T₁ = 3 and Tₙ = Tₙ₋₁ + 4. What is T₆?

Accepted Answer

23

Answer

19

Answer

21

Answer

27

Question 7

Evaluate: ∑ₖ₌₁⁵ (2k − 1)

Accepted Answer

25

Answer

20

Answer

30

Answer

35