Foundation June 2017 Paper 3 Q10
10
(a) Write down the second and third terms of the following two sequences.
(i) Rule : To get the next term subtract 4 from the previous term.
First term = 19.\[19 \qquad \ldots\ldots\ldots \qquad \ldots\ldots\ldots\]
First term = 19.\[19 \qquad \ldots\ldots\ldots \qquad \ldots\ldots\ldots\]
[1]
(ii) Rule : To get the next term multiply the previous term by 5 and then add 3.
First term = 7.\[7 \qquad \ldots\ldots\ldots \qquad \ldots\ldots\ldots\]
First term = 7.\[7 \qquad \ldots\ldots\ldots \qquad \ldots\ldots\ldots\]
[1]
(b) Here are the first four terms of another sequence.\[5 \qquad 9 \qquad 13 \qquad 17\]
Write an expression for the \(n\)th term of this sequence. [2]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| (i) 15 11 | 1 | ||
| (ii) 38 193 | 1 | ||
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(4n + 1\) oe | 2 | B1 for \(4n + k\) \(k\) may be 0 | Accept \(n4\) (if clear this is not \(n^4\)) and \(n \times 4\) and \(4 \times n\) oe \(5 + (n - 1) \times 4\) scores 2 marks Condone \(x = \ldots\) and \(n^{\text{th}} = \ldots\) for 2 marks Condone \(n = 4n + 1\) for 1 mark |