| Exam Board | Edexcel |
|---|---|
| Module | D1 (Decision Mathematics 1) |
| Year | 2002 |
| Session | June |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Sorting Algorithms |
| Type | Quick Sort Execution |
| Difficulty | Easy -1.8 This is a purely mechanical execution of the quick sort algorithm on a small dataset (9 items) with clear numerical values. It requires only recall of the algorithm steps and careful bookkeeping, with no problem-solving, proof, or conceptual understanding beyond the procedure itself. Significantly easier than average A-level maths questions. |
| Spec | 7.03k Sorting: quick sort |
| Ashford | 6 |
| Colnbrook | 1 |
| Datchet | 18 |
| Feltham | 12 |
| Halliford | 9 |
| Laleham | 0 |
| Poyle | 5 |
| Staines | 13 |
| Wraysbury | 14 |
| Answer | Marks | Guidance |
|---|---|---|
| \(a\) | \(b\) | \(c\) |
| 645 | 255 | 2.53 |
| 255 | 135 | 1.89 |
| 135 | 120 | 1.13 |
| 120 | 15 | 8 |
| Finds the H.C.F of \(a\) and \(b\) | M1 A1 |
| Answer | Marks |
|---|---|
| The answer is 15 | A1 |
| Answer | Marks | Guidance |
|---|---|---|
| \(a\) | \(b\) | \(c\) |
| 255 | 645 | 0.40 |
| But the second row would then be the same as the first row above, and the solution thereafter would be the same. | M1 A1 |
| Answer | Marks | Guidance |
|---|---|---|
| A | E | D |
| C | G | H |
| B | F | J |
| A1 A1 A1 (7) |
| Answer | Marks |
|---|---|
| \(x + y \geq 380\) | B1 |
| \(y \geq 125\) | B1 |
| \(2x + 4y \leq 1200\) | B1 |
| Answer | Marks |
|---|---|
| \(c = 3x + 2y\) | B1 |
| Answer | Marks |
|---|---|
| B1 B1 B1 B1 (4) |
| Answer | Marks |
|---|---|
| Use of profit line or points testing | M1 |
| Answer | Marks |
|---|---|
| \(x = 160\), \(y = 120\), cost \(= £920\) | A1 A1 (3) |
| Answer | Marks |
|---|---|
| \(x = 350\), \(y = 125\), cost \(= £1300\) | M1 A1 A1 (3) |
# Question 5
## (a)
| $a$ | $b$ | $c$ | $d$ | $e$ | $f$ | $f = 0$? |
|---|---|---|---|---|---|---|
| 645 | 255 | 2.53 | 2 | 510 | 135 | No |
| 255 | 135 | 1.89 | 1 | 135 | 120 | No |
| 135 | 120 | 1.13 | 1 | 120 | 15 | No |
| 120 | 15 | 8 | 8 | 120 | 0 | Yes |
Finds the H.C.F of $a$ and $b$ | M1 A1
## (b)
The answer is 15 | A1
The first row would be
| $a$ | $b$ | $c$ | $d$ | $e$ | $f$ | $f = 0$? |
|---|---|---|---|---|---|---|
| 255 | 645 | 0.40 | 0 | 0 | 255 | No |
But the second row would then be the same as the first row above, and the solution thereafter would be the same. | M1 A1
## (c)
| A | E | D | I | L | P |
| C | G | H | M |
| B | F | J | K | N |
| A1 A1 A1 (7)
(11 marks total)
---
# Question 8
## (a)
$x + y \geq 380$ | B1
$y \geq 125$ | B1
$2x + 4y \leq 1200$ | B1
(3 marks)
## (b)
$c = 3x + 2y$ | B1
(1 mark)
## (c)
Graph showing feasible region with lines:
- $x + y = 380$
- $y = 125$
- $2x + 4y = 1200$
| B1 B1 B1 B1 (4)
## (d)
Use of profit line or points testing | M1
Minimum at intersection of $x + y = 380$ and $2x + 4y = 1200$
$x = 160$, $y = 120$, cost $= £920$ | A1 A1 (3)
Maximum at intersection of $y = 125$ and $2x + 4y = 1200$
$x = 350$, $y = 125$, cost $= £1300$ | M1 A1 A1 (3)
(14 marks total)
1.
\begin{center}
\begin{tabular}{ | l | c | }
\hline
Ashford & 6 \\
\hline
Colnbrook & 1 \\
\hline
Datchet & 18 \\
\hline
Feltham & 12 \\
\hline
Halliford & 9 \\
\hline
Laleham & 0 \\
\hline
Poyle & 5 \\
\hline
Staines & 13 \\
\hline
Wraysbury & 14 \\
\hline
\end{tabular}
\end{center}
The table above shows the points obtained by each of the teams in a football league after they had each played 6 games. The teams are listed in alphabetical order. Carry out a quick sort to produce a list of teams in descending order of points obtained.\\
\hfill \mbox{\textit{Edexcel D1 2002 Q1 [5]}}