Paper 2 Algorithmic Representation Drills

These are original topic-local Paper 2-style drills, not a complete four-question Paper 2. They use exact function names, return values, test calls, and expected output evidence.

Detailed answers are in Paper 2 Algorithmic Representation Answers.

Revise the topic hub first:

• Algorithmic Representation

Questions

Question 1: Pseudocode to Python

Convert this pseudocode into a Python function ticket_type(age).

IF age < 13 THEN
    result <- "Child"
ELSE IF age < 60 THEN
    result <- "Adult"
ELSE
    result <- "Senior"
ENDIF
 
RETURN result

Test:

print(ticket_type(10))
print(ticket_type(35))
print(ticket_type(60))

Expected output:

Child
Adult
Senior

[6]

Question 2: Sentinel Loop

Write a function total_before_sentinel(values) that represents this sentinel-controlled algorithm:

• read values from the list in order;
• stop when the value is -1;
• return the sum of values before -1;
• ignore -1 and any values after -1.

Test:

print(total_before_sentinel([12, 8, 15, -1, 100]))
print(total_before_sentinel([-1, 50]))

Expected output:

35
0

[6]

Question 3: Decision Table Function

A learner may start an online quiz only when:

logged_in AND quiz_open AND attempts_left

Write a function quiz_action(logged_in, quiz_open, attempts_left) that returns "START" or "WAIT".

Test:

print(quiz_action(True, True, True))
print(quiz_action(True, True, False))
print(quiz_action(False, True, True))

Expected output:

START
WAIT
WAIT

[5]

Question 4: Trace by Print

Write a function trace_double_total() that follows this algorithm and prints the state after each iteration.

count <- 1
total <- 0
 
WHILE count <= 4
    total <- total + (count * 2)
    OUTPUT count, total
    count <- count + 1
ENDWHILE

Expected output:

1 2
2 6
3 12
4 20

[5]

Question 5: Modular Program

Write four functions:

• get_hours() returns [2, 0, 3];
• calculate_total(hours) returns the total number of hours;
• format_total(total) returns "Total hours: 5" for the test data;
• main() calls the functions in sequence and prints the display string.

Expected output when main() is called:

Total hours: 5

[8]

Question 6: Flowchart Implementation

Implement the following flowchart description as a function count_passing(marks).

Start
count <- 0
FOR each mark in marks
    Decision: mark >= 50?
    Yes: count <- count + 1
    No: do not change count
NEXT mark
Return count
End

Test:

print(count_passing([72, 49, 50, 38, 91]))

Expected output:

3

[7]

Question 7: Validation Function

Write and test a function valid_percentage(mark) that returns True only when mark is an integer from 0 to 100 inclusive.

Test:

print(valid_percentage(-1))
print(valid_percentage(0))
print(valid_percentage(100))
print(valid_percentage(101))
print(valid_percentage(50.5))

Expected output:

False
True
True
False
False

[5]

Question 8: Pseudocode Bug Fix

This flawed condition rejects valid boundary marks:

IF mark > 0 AND mark < 100 THEN
    valid <- True
ELSE
    valid <- False
ENDIF

Write a corrected Python function fixed_valid_percentage(mark) that returns True only when mark is an integer from 0 to 100 inclusive.

Test:

print(fixed_valid_percentage(0))
print(fixed_valid_percentage(50))
print(fixed_valid_percentage(100))
print(fixed_valid_percentage(50.5))

Expected output:

True
True
True
False

[6]

Question 9: Complete Decision-Table Tests

Reuse quiz_action(logged_in, quiz_open, attempts_left) from Question 3.

Write a function quiz_decision_table_tests() that returns a list of result strings for these eight cases, in the given order:

[
    (True, True, True),
    (True, True, False),
    (True, False, True),
    (True, False, False),
    (False, True, True),
    (False, True, False),
    (False, False, True),
    (False, False, False)
]

Expected output:

['START', 'WAIT', 'WAIT', 'WAIT', 'WAIT', 'WAIT', 'WAIT', 'WAIT']

[5]

Question 10: Program Skeleton

Create a runnable Python skeleton for a booking program with these functions:

• read_booking_request()
• validate_request(request)
• store_booking(requests, request)
• display_summary(requests)
• main()

For this skeleton, use placeholders so that running main() prints:

Accepted bookings: 0

[5]

Review Checklist

After attempting these questions, check whether you can:

• translate pseudocode selection and loops into Python;
• distinguish return values from printed output;
• implement a decision-table rule as Boolean logic;
• print trace evidence without changing the algorithm;
• split code into named modules with clear responsibilities;
• test boundary cases and all major actions.