Topic 8 Practice Paper: Sequences — question paper
IGCSE · Cambridge IGCSE Mathematics (Extended (Core + Extended))
Topic 8 Practice Paper
Sequences
READ THESE INSTRUCTIONS FIRST
- Answer all questions.
- Section A contains ten multiple-choice questions. Choose one answer, A, B, C or D, for each.
- Section B contains structured questions. Write your answers in the spaces provided.
- The number of marks is given in brackets [ ] at the end of each question or part question.
- The total mark for this paper is 30.
Original practice material written against the Cambridge IGCSE Mathematics syllabus. It is not an official Cambridge examination paper. Topic 8: term-to-term rules, nth terms of linear, quadratic and cubic sequences, geometric (exponential) patterns, and term-hunting questions on patterns and positions.
| For Examiner’s Use | |
|---|---|
| Section A | / 10 |
| Section B | / 20 |
| Total | / 30 |
Section A: Multiple-choice questions[10 marks]
Choose one answer for each question. Every correct answer scores one mark.
- 1( )
What comes after 11, 15, 19, 23 in this list?
- A25
- B27
- C31
- D26
- 2( )
For 7, 12, 17, 22, …, the rule for term n is
- A5n − 2
- B5n + 7
- C5n + 2
- D7n − 5
- 3( )
Given the rule 4n − 3 for every term, work out term number 15.
- A57
- B60
- C63
- D45
- 4( )
Which expression generates 9, 4, −1, −6, …?
- A5n + 14
- B−5n + 4
- C−5n − 4
- D−5n + 14
- 5( )
Write down the next term of 1, 3, 9, 27, ….
- A72
- B81
- C90
- D243
- 6( )
Substituting n = 1, 2, 3, 4 into 2n² − 1 gives
- A2, 6, 12, 20
- B1, 4, 9, 16
- C1, 7, 17, 31
- D0, 5, 14, 27
- 7( )
Evaluate the term in position 6 of the sequence whose rule is 2ⁿ. (Extended)
- A64
- B32
- C128
- D12
- 8( )
108 sits in which position of the sequence generated by 7n − 4?
- A15th
- B108th
- C14th
- D16th
- 9( )
Which rule matches the list 3, 6, 11, 18, …?
- An² − 2
- Bn² + 2
- C2n²
- Dn² + 3
- 10( )
Tripling from a start of four generates 4, 12, 36, 108, … Its position-n formula is (Extended)
- A4 × 3ⁿ
- B12 × 3ⁿ
- C4 × 3ⁿ⁻¹
- D4 × 3ⁿ⁺¹
Section B: Structured questions[20 marks]
Answer all questions in the spaces provided. Show all your working.
- 11
A sequence starts 96, 89, 82, 75, ….
- (a)
Continue the list for two more terms.
[1] - (b)
Find the nth term of the sequence.
[2] - (c)
Is 0 one of the terms? Justify your answer.
[2]
- (a)
- 12
A sequence has nth term n² + 3n.
- (a)
Write down the first four terms.
[2] - (b)
One of the terms is 130. Which position does it occupy?
[3]
- (a)
- 13
A sequence starts 625, 125, 25, 5, …. (Extended)
- (a)
Write down the two terms that follow the 5.
[1] - (b)
Find an expression for the nth term.
[3] - (c)
Which term equals 1⁄25?
[1]
- (a)
- 14
Dots are arranged in triangles: pattern 1 has 1 dot, pattern 2 has 3 dots, pattern 3 has 6 dots, pattern 4 has 10 dots. (Extended)
- (a)
Write down the number of dots in pattern 5.
[1] - (b)
Show that the second differences are constant.
[1] - (c)
Prove that the number of dots in pattern n equals n(n + 1)⁄2.
[2] - (d)
Determine whether 120 dots can form one of these triangles.
[1]
- (a)
— End of paper —