| Exam Board | Edexcel |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Topic | Arithmetic Sequences and Series |
| Type | Sum of multiples or integers |
| Difficulty | Moderate -0.3 This is a straightforward application of arithmetic series formulas. Part (a) requires identifying the sequence 7, 14, 21, ..., 994 and applying the sum formula - a standard textbook exercise. Part (b) uses the result from (a) with simple algebraic manipulation of the summation. While it requires multiple steps and understanding of series notation, it involves only routine techniques with no problem-solving insight needed, making it slightly easier than average for A-level. |
| Spec | 1.04g Sigma notation: for sums of series1.04h Arithmetic sequences: nth term and sum formulae |
\begin{enumerate}[label=(\alph*)]
\item Find the sum of all the integers between 1 and 1000 which are divisible by 7. [3]
\item Hence, or otherwise, evaluate $\sum_{r=1}^{142} (7r + 2)$. [3]
\end{enumerate}
\hfill \mbox{\textit{Edexcel C1 Q13 [6]}}