Time allowed: 45 minutes
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INSTRUCTIONS
- Use black ink.
- Answer all the questions.
INFORMATION
- The total mark for this paper is 30.
- The marks for each question are shown in brackets [ ].
Turn over
Section A: Core Concepts & Indexing
1
A program uses a list (1D array) called
scores to store the test results of 5 students:
[10, 50, 60, 20, 90].
Fill in the missing Python / OCR Reference Language keywords to calculate the total.
total = 0
for i = 0 to ......................... - 1
total = total + scores[.........................]
next i
print(total)
[2]
2
Explain
two benefits of using an Array to store 100 student names compared to creating 100 separate variables (e.g.,
name1,
name2...).
[2]
3
A 2D array named
seating_plan stores the names of students in a classroom. The array is indexed as
seating_plan[row, column].
| Col 0 | Col 1 | Col 2 |
|---|
| Row 0 | "Ali" | "Bea" | "Caz" |
|---|
| Row 1 | "Dan" | "Eve" | "Fay" |
|---|
(a) State the data stored at
seating_plan[1, 0].
[1]
(b) State the data stored at
seating_plan[0, 2].
[1]
(c) A student writes
print(seating_plan[2, 0]). State what will happen and explain why.
[2]
Turn over
Section B: Debugging & Tracing
4
A developer is using a 2D array called
stock to emulate a database table of products.
- Column 0: Product Name (String)
- Column 1: Price (Real)
- Column 2: Quantity (Integer)
Current Data in
stock:
[ ["Apple", 0.50, 100], ["Banana", 0.30, 150], ["Pear", 0.40, 80] ]
The programmer wants to reduce the Quantity of "Apples" by 1. They write:
stock[0, 1] = stock[0, 1] - 1
(a) Identify the
Logic Error in this line of code.
[1]
(b) Write the corrected line of code.
[1]
5
Trace the following algorithm which uses a 2D array named
grid.
grid = [ [1, 2], [3, 4] ]
total = 0
for r = 0 to 1
for c = 0 to 1
if grid[r, c] > 2 then
total = total + grid[r, c]
else
total = total - 1
endif
next c
next r
print(total)
[4]
| r |
c |
grid[r, c] |
total |
| 0 | 0 | 1 | -1 |
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Turn over
Section C: Coding & Application
6
A student writes a program to store phone numbers in an array.
contacts = [07700900123, 07700900456, 07700900789]
When they print the numbers, the leading zeros are missing (e.g.,
7700900123).
(a) Explain why the leading zeros have been removed.
[1]
(b) Rewrite the array declaration so the leading zeros are preserved.
[1]
7
A teacher stores marks for 3 tests for 4 students in a 2D array called
marks.
Rows represent Students (0 to 3). Columns represent Tests (0 to 2).
Example Data:
| Test0 | Test1 | Test2 |
|---|
| Stu0 | 10 | 20 | 30 |
| Stu1 | 50 | 50 | 50 |
| Stu2 | 5 | 5 | 5 |
| Stu3 | 100 | 90 | 80 |
Write an algorithm (in Python or OCR Reference Language) that:
- Asks the user to input a Student ID (0-3).
- Calculates the average score for that specific student across their 3 tests.
- Outputs the average.
[6]
8
Write an algorithm to search the whole
marks array (from Question 7) to find if any student scored 100 in any test.
- If 100 is found, output "Found".
- If the loops finish and 100 was never found, output "Not Found".
[6]
END OF QUESTION PAPER