| Exam Board | OCR MEI |
|---|---|
| Module | Paper 2 (Paper 2) |
| Year | 2020 |
| Session | November |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Arithmetic Sequences and Series |
| Type | Find term or common difference |
| Difficulty | Moderate -0.8 This is a straightforward arithmetic sequence question requiring only standard formulas. Part (a) uses the nth term formula to find n, and part (b) applies the sum formula. Both are direct applications of memorized formulas with no problem-solving insight needed, making it easier than average but not trivial since it requires careful arithmetic with larger numbers. |
| Spec | 1.04h Arithmetic sequences: nth term and sum formulae |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| \(26\) | B1 | NB \(17 + (n-1) \times 11 = 292\) |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| \(\frac{\text{their } 26}{2} \times (17 + 292)\) oe | M1 | \(\frac{\text{their } 26}{2} \times (2 \times 17 + (\text{their } 26 - 1) \times 11)\) |
| \(4017\) | A1 |
## Question 5:
### Part (a):
| Answer | Marks | Guidance |
|--------|-------|----------|
| $26$ | B1 | NB $17 + (n-1) \times 11 = 292$ |
### Part (b):
| Answer | Marks | Guidance |
|--------|-------|----------|
| $\frac{\text{their } 26}{2} \times (17 + 292)$ oe | M1 | $\frac{\text{their } 26}{2} \times (2 \times 17 + (\text{their } 26 - 1) \times 11)$ |
| $4017$ | A1 | |
---5 The first $n$ terms of an arithmetic series are\\
$17 + 28 + 39 + \ldots + 281 + 292$.
\begin{enumerate}[label=(\alph*)]
\item Find the value of $n$.
\item Find the sum of these $n$ terms.
\end{enumerate}
\hfill \mbox{\textit{OCR MEI Paper 2 2020 Q5 [3]}}