| Exam Board | OCR MEI |
|---|---|
| Module | C2 (Core Mathematics 2) |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Arithmetic Sequences and Series |
| Type | Sum of specific range of terms |
| Difficulty | Moderate -0.8 This is a straightforward arithmetic progression question requiring only standard formulas. Part (i) involves finding the common difference and applying the nth term formula. Part (ii) requires calculating a partial sum using the standard sum formula. Both parts are routine applications with no problem-solving insight needed, making this easier than average. |
| Spec | 1.04h Arithmetic sequences: nth term and sum formulae |
| Answer | Marks |
|---|---|
| 7 | (i) 54.5 |
| Answer | Marks |
|---|---|
| 2797.5 c.a.o. | 2 |
| Answer | Marks |
|---|---|
| A1 | B1 for d = 2.5 |
| Answer | Marks |
|---|---|
| M1 if one slip | 5 |
Question 7:
7 | (i) 54.5
(ii)Correct use of sum of AP
formula with n = 50, 20, 19 or 21
with their d and a = 7 eg S =
50
3412.5, S = 615
20
Their S − S dep on use of ap
50 20
formula
2797.5 c.a.o. | 2
M1
M1
A1 | B1 for d = 2.5
or M2 for correct formula for S with
30
their d
M1 if one slip | 5An arithmetic progression has first term 7 and third term 12.
\begin{enumerate}[label=(\roman*)]
\item Find the 20th term of this progression. [2]
\item Find the sum of the 21st to the 50th terms inclusive of this progression. [3]
\end{enumerate}
\hfill \mbox{\textit{OCR MEI C2 Q7 [5]}}