| Exam Board | OCR MEI |
|---|---|
| Module | C2 (Core Mathematics 2) |
| Year | 2014 |
| Session | June |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Arithmetic Sequences and Series |
| Type | Sigma notation: direct numerical evaluation |
| Difficulty | Moderate -0.8 Part (i) is straightforward summation of five terms by direct substitution. Part (ii) involves recognizing an arithmetic sequence and applying standard formulas for the nth term and sum—routine bookwork with no problem-solving required. Both parts are below average difficulty for A-level, requiring only basic recall and arithmetic. |
| Spec | 1.04e Sequences: nth term and recurrence relations1.04g Sigma notation: for sums of series1.04h Arithmetic sequences: nth term and sum formulae |
\begin{enumerate}[label=(\roman*)]
\item Find $\sum_{r=1}^{5} \frac{21}{r+2}$. [2]
\item A sequence is defined by
$$u_1 = a, \text{ where } a \text{ is an unknown constant,}$$
$$u_{n+1} = u_n + 5.$$
Find, in terms of $a$, the tenth term and the sum of the first ten terms of this sequence. [3]
\end{enumerate}
\hfill \mbox{\textit{OCR MEI C2 2014 Q2 [5]}}