Foundation June 2024 Paper 2 Q15
15 A linear sequence begins
2 5 8 11
Work out an expression for the \(n\)th term. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(3n - 1\) | B2 | oe eg \(2 + (3n - 3)\) B1 \(3n + c\) where \(c\) can be any value |
Additional guidance
| Ignore LHS of formula given eg \(\mathrm{T}_n = 3n - 1\) | B2 |
| Condone \(n = 3n - 1\) or \(n\)th term \(= 3n - 1\) | B2 |
| Allow a multiplication sign eg \(3 \times n - 1\) or \(n \times 3 - 1\) | B2 |
| Allow other variables eg \(3x - 1\) | B2 |
| \(3n + -1\) | B1 |
| \(3x\) | B1 |
| \(n3\) … | B1 |
| \(n3 - 1\) | B1 |
| \(3n\)th \(- 1\) | B1 |
| \(3n\)th | B0 |
| \(n3 - 1n\) | B0 |