Last full Paper 2

Check the date, the time and the room of each paper.

• Two black or dark blue pens.
• A pencil, a ruler and an eraser for diagrams and logic circuits.
• A simple watch. Smartwatches are not allowed.
• No calculator. It is not allowed in either Computer Science paper.

1. Read the instructions on the front cover.
2. Write your clock times for the paper on the front page.
3. For each question: underline the command word and circle the marks.
4. Answer every question. A blank always scores zero.
5. In the last 10 minutes, check: working, units, trace tables, and starred questions.

Totalling means adding values into a running total: `Total ← Total + Value`.

Counting means adding 1 each time something happens: `Count ← Count + 1`.

Both variables must start at 0 before the loop.

DECLARE Marks : ARRAY[1:6] OF INTEGER
DECLARE Index : INTEGER
DECLARE Total : INTEGER
DECLARE PassCount : INTEGER
// Marks already holds 34, 48, 21, 40, 15, 45
Total ← 0
PassCount ← 0
FOR Index ← 1 TO 6
  Total ← Total + Marks[Index]
  IF Marks[Index] >= 25
    THEN
      PassCount ← PassCount + 1
  ENDIF
NEXT Index
OUTPUT "Total: ", Total
OUTPUT "Number of passes: ", PassCount

marks = [34, 48, 21, 40, 15, 45]
total = 0
pass_count = 0
for index in range(6):
    total = total + marks[index]
    if marks[index] >= 25:
        pass_count = pass_count + 1
print("Total:", total)
print("Number of passes:", pass_count)

This formula is not in the syllabus. It is useful for understanding why bubble sort is slow for long lists.

In the worst case every pass is needed. With n items, pass 1 makes n − 1 comparisons, pass 2 makes n − 2, and so on down to 1.

Adding these gives n(n − 1) ÷ 2. Double the list and the work goes up about four times.

The lesson page has the rest of the explanation, step by step:

• Finding the maximum and minimum
• Finding the average
• Linear search
• Bubble sort
• Be precise, and amend with care
• The 15-mark scenario question: plan first
• Model answer in pseudocode and Python
• How the 15 marks are awarded
• The shape of a query
• Predicting output: one condition
• AND: both conditions must be true
• OR: at least one condition must be true

Open the lesson page