1MA0 Higher November 2015 Paper 1 Q3
3 Here are the first four terms of an arithmetic sequence.
11 17 23 29
(a) Find, in terms of \(n\), an expression for the \(n\)th term of this arithmetic sequence. (2)
(b) Is 121 a term of this arithmetic sequence?
You must explain your answer. (2)
You must explain your answer. (2)
| Answer | Mark | Notes |
|---|---|---|
| \(6n + 5\) | 2 | B2 for \(6n + 5\) (B1 for \(6n + k\) where \(k\) is an integer or absent) |
| Answer | Mark | Notes |
|---|---|---|
| No with explanation | 2 | M1 for "\(6n + 5\)" = 121 or any other valid method, e.g. counting on 6s (to get to 119 or more) A1 for No with complete explanation, e.g. \(6n = 116\) will not give a whole number |