4MA0 Foundation January 2015 Paper 1 Q5
5 Here are the first five terms of a number sequence.
13 20 27 34 41
(a) Write down the next two terms of the sequence. (2)
(b) Explain how you worked out your answer. (1)
(c) Work out the 20th term of the sequence. (2)
| Scheme | Marks |
|---|---|
| 48 | B1 |
| 55 | B1 |
| (2) |
Notes
B1: shown as sixth term
B1: shown as seventh term
ft from their (a) “48” + 7
| Scheme | Marks |
|---|---|
| Added 7 | B1 |
| (1) |
Notes
B1: accept +7, 7 more, jumped forward by 7, difference = 7 oe or \(7n + 6\)
| Scheme | Marks |
|---|---|
| 13 + 19 × 7 or 20 × 7 + 6 or \(7n + 6\) Or 13, 20, 27, …., 139, 146 (list of 20 terms) | M1 |
| 146 | A1 |
| (2) | |
| (5 marks) |
Notes
M1: allow 13 + 20 × 7 or 139 or 153
List should show a clear intention of adding 7 with at least 5 terms (including 55). Condone 1 arithmetic error.
Eg 55, 62, 69, 76, 82
Eg 48, 55, 62, 69, 76, 82
A1: May be seen as the last term in a list