| Exam Board | OCR MEI |
|---|---|
| Module | C2 (Core Mathematics 2) |
| Year | 2016 |
| Session | June |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Arithmetic Sequences and Series |
| Type | Periodic or repeating sequence |
| Difficulty | Moderate -0.8 This is a straightforward sequence question requiring only basic arithmetic operations (finding remainders mod 3, multiplying by 5) and simple summation. The process is clearly defined with no conceptual difficulty, making it easier than average for A-level, though it requires careful execution of the algorithm. |
| Spec | 1.04e Sequences: nth term and recurrence relations1.04g Sigma notation: for sums of series |
A sequence is defined as follows.
$u_1 = a$, where $a > 0$
To obtain $u_{r+1}$
\begin{itemize}
\item find the remainder when $u_r$ is divided by 3,
\item multiply the remainder by 5,
\item the result is $u_{r+1}$.
\end{itemize}
Find $\sum_{r=2}^4 u_r$ in each of the following cases.
\begin{enumerate}[label=(\roman*)]
\item $a = 5$
\item $a = 6$ [3]
\end{enumerate}
\hfill \mbox{\textit{OCR MEI C2 2016 Q2 [3]}}