| Exam Board | OCR MEI |
|---|---|
| Module | S1 (Statistics 1) |
| Year | 2007 |
| Session | June |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Combinations & Selection |
| Type | Basic committee/group selection |
| Difficulty | Easy -1.2 This is a straightforward application of basic combinations (8C4) and permutations (4!), requiring only direct formula recall with no problem-solving or multi-step reasoning. It's easier than average A-level material, being a standard S1 introductory exercise. |
| Spec | 5.01a Permutations and combinations: evaluate probabilities5.01b Selection/arrangement: probability problems |
| Answer | Marks | Guidance |
|---|---|---|
| \(\binom{8}{4}\) ways to select \(= 70\) | M1 for \(\binom{8}{4}\), A1 CAO | 2 marks |
| Answer | Marks | Guidance |
|---|---|---|
| \(4! = 24\) | B1 CAO | 1 mark |
# Question 1:
## Part (i)
$\binom{8}{4}$ ways to select $= 70$ | M1 for $\binom{8}{4}$, A1 CAO | 2 marks
## Part (ii)
$4! = 24$ | B1 CAO | 1 mark
---1 A girl is choosing tracks from an album to play at her birthday party. The album has 8 tracks and she selects 4 of them.\\
(i) In how many ways can she select the 4 tracks?\\
(ii) In how many different orders can she arrange the 4 tracks once she has chosen them?
\hfill \mbox{\textit{OCR MEI S1 2007 Q1 [3]}}