90 min read

Programming Practice Exam: Answer Sheet

Model answers, working and marking points for the Programming Practice Exam.

How to Use This Answer Sheet

Try the practice paper first, then compare. For calculations, check each step, not just the final answer. For written answers, the model answers show the points a marker looks for — your wording can be different, and other sensible choices with good reasons also earn marks.

Section I — Answers

Multiple-choice answers
Multiple-choice answers

Question 1 — Sequence

Question 1(a) — model flowchart

Read this flowchart as text

Terminator: Start (then → INPUT student_id)
Input/output: INPUT student_id (then → INPUT name)
Input/output: INPUT name (then → INPUT fee)
Input/output: INPUT fee (then → discount = fee × 0.15)
Process: discount = fee × 0.15 (then → amount = fee − discount)
Process: amount = fee − discount (then → OUTPUT discount, amount)
Input/output: OUTPUT discount, amount (then → Stop)
Terminator: Stop

Question 1(b) — model codePython

1# fees.py - class fee with a 15% sibling discount2student_id = input("Student ID: ")3name = input("Name: ")4fee = float(input("Monthly fee (LKR): "))5 6discount = fee * 0.157amount = fee - discount8 9print(f"Student: {student_id} {name}")10print(f"Discount: LKR {discount:,.2f}")11print(f"Amount to pay: LKR {amount:,.2f}")

Inputs (one per line — used by input() in order)

Expected output

Student ID: S1024
Name: Nimali Fernando
Monthly fee (LKR): 4500
Student: S1024 Nimali Fernando
Discount: LKR 675.00
Amount to pay: LKR 3,825.00

Marking points: inputs in parallelograms; the two calculations in rectangles, in the right order; output of both values; float() for the fee; clear prompts and formatted output. Using a constant such as DISCOUNT_RATE = 0.15 is good practice.

Question 2 — Nested Selection

Question 2(a) — model flowchart

Read this flowchart as text

Terminator: Start (then → INPUT service, quantity)
Input/output: INPUT service, quantity (then → service is 1, 2 or 3?)
Decision: service is 1, 2 or 3? (Yes → service = 1?; No → OUTPUT "Invalid service")
Input/output: OUTPUT "Invalid service" (then → Stop)
Decision: service = 1? (Yes → rate = 350; No → service = 2?)
Process: rate = 350 (then → total = rate × quantity)
Decision: service = 2? (Yes → rate = 500; No → rate = 900)
Process: rate = 500 (then → total = rate × quantity)
Process: rate = 900 (then → total = rate × quantity)
Process: total = rate × quantity (then → OUTPUT total)
Input/output: OUTPUT total (then → Stop)
Terminator: Stop

The first decision rejects an invalid service; the inner decisions choose the rate.

Question 2(b) — model codePython

1# laundry.py - total cost for a laundry service2print("1. Wash and fold (LKR 350 per kg)")3print("2. Wash and iron (LKR 500 per kg)")4print("3. Dry cleaning (LKR 900 per item)")5service = int(input("Service type (1-3): "))6quantity = int(input("Quantity (kg or items): "))7 8if 1 <= service <= 3:9    if service == 1:10        rate = 35011    elif service == 2:12        rate = 50013    else:14        rate = 90015    total = rate * quantity16    print(f"Total cost: LKR {total:,}")17else:18    print("Invalid service")

Inputs (one per line — used by input() in order)

Expected output

1. Wash and fold (LKR 350 per kg)
2. Wash and iron (LKR 500 per kg)
3. Dry cleaning (LKR 900 per item)
Service type (1-3): 2
Quantity (kg or items): 4
Total cost: LKR 2,000

The nesting is the if/elif/else inside the first if. Another correct answer nests each test in the else of the one before (if service == 1: \dots else: if service == 2: \dots). Test with 1, 2 and 3, and with an invalid value such as 5 or 0.

Question 3 — A Loop

Question 3(a) — model flowchart

Read this flowchart as text

Terminator: Start (then → n = 0)
Process: n = 0 (then → n <= 30?)
Decision: n <= 30? (Yes → OUTPUT n; No → Stop)
Input/output: OUTPUT n (then → n = n + 3)
Terminator: Stop
Process: n = n + 3 (then → n <= 30?)

Start value, condition, change: n = 0, n <= 30?, n = n + 3.

Question 3(b) — model code (while)Python

1# multiples.py - multiples of 3 from 0 to 30 (while loop, matching the flowchart)2n = 03while n <= 30:4    print(n)5    n = n + 3

Expected output

Also correct — a for loopPython

1for n in range(0, 31, 3):2    print(n)

Expected output

Watch the end value: range(0, 30, 3) stops before 30, so 30 would be missing. The stop value must be 31 (anything above 30 and up to 33 works, but 31 is clearest). In the while loop, <= includes 30.

More lessons in Python Programming · Next: Course Exam · Previous: Programming Practice Exam

Section I — Answers

Multiple-choice answers
Multiple-choice answers

Question 1 — Sequence

Question 1(a) — model flowchart

Read this flowchart as text

Terminator: Start (then → INPUT student_id)
Input/output: INPUT student_id (then → INPUT name)
Input/output: INPUT name (then → INPUT fee)
Input/output: INPUT fee (then → discount = fee × 0.15)
Process: discount = fee × 0.15 (then → amount = fee − discount)
Process: amount = fee − discount (then → OUTPUT discount, amount)
Input/output: OUTPUT discount, amount (then → Stop)
Terminator: Stop

Question 1(b) — model codePython

1# fees.py - class fee with a 15% sibling discount2student_id = input("Student ID: ")3name = input("Name: ")4fee = float(input("Monthly fee (LKR): "))5 6discount = fee * 0.157amount = fee - discount8 9print(f"Student: {student_id} {name}")10print(f"Discount: LKR {discount:,.2f}")11print(f"Amount to pay: LKR {amount:,.2f}")

Inputs (one per line — used by input() in order)

Expected output

Student ID: S1024
Name: Nimali Fernando
Monthly fee (LKR): 4500
Student: S1024 Nimali Fernando
Discount: LKR 675.00
Amount to pay: LKR 3,825.00

Marking points: inputs in parallelograms; the two calculations in rectangles, in the right order; output of both values; float() for the fee; clear prompts and formatted output. Using a constant such as DISCOUNT_RATE = 0.15 is good practice.

Question 2 — Nested Selection

Question 2(a) — model flowchart

Read this flowchart as text

Terminator: Start (then → INPUT service, quantity)
Input/output: INPUT service, quantity (then → service is 1, 2 or 3?)
Decision: service is 1, 2 or 3? (Yes → service = 1?; No → OUTPUT "Invalid service")
Input/output: OUTPUT "Invalid service" (then → Stop)
Decision: service = 1? (Yes → rate = 350; No → service = 2?)
Process: rate = 350 (then → total = rate × quantity)
Decision: service = 2? (Yes → rate = 500; No → rate = 900)
Process: rate = 500 (then → total = rate × quantity)
Process: rate = 900 (then → total = rate × quantity)
Process: total = rate × quantity (then → OUTPUT total)
Input/output: OUTPUT total (then → Stop)
Terminator: Stop

The first decision rejects an invalid service; the inner decisions choose the rate.

Question 2(b) — model codePython

1# laundry.py - total cost for a laundry service2print("1. Wash and fold (LKR 350 per kg)")3print("2. Wash and iron (LKR 500 per kg)")4print("3. Dry cleaning (LKR 900 per item)")5service = int(input("Service type (1-3): "))6quantity = int(input("Quantity (kg or items): "))7 8if 1 <= service <= 3:9    if service == 1:10        rate = 35011    elif service == 2:12        rate = 50013    else:14        rate = 90015    total = rate * quantity16    print(f"Total cost: LKR {total:,}")17else:18    print("Invalid service")

Inputs (one per line — used by input() in order)

Expected output

1. Wash and fold (LKR 350 per kg)
2. Wash and iron (LKR 500 per kg)
3. Dry cleaning (LKR 900 per item)
Service type (1-3): 2
Quantity (kg or items): 4
Total cost: LKR 2,000

The nesting is the if/elif/else inside the first if. Another correct answer nests each test in the else of the one before (if service == 1: \dots else: if service == 2: \dots). Test with 1, 2 and 3, and with an invalid value such as 5 or 0.

Question 3 — A Loop

Question 3(a) — model flowchart

Read this flowchart as text

Terminator: Start (then → n = 0)
Process: n = 0 (then → n <= 30?)
Decision: n <= 30? (Yes → OUTPUT n; No → Stop)
Input/output: OUTPUT n (then → n = n + 3)
Terminator: Stop
Process: n = n + 3 (then → n <= 30?)

Start value, condition, change: n = 0, n <= 30?, n = n + 3.

Question 3(b) — model code (while)Python

1# multiples.py - multiples of 3 from 0 to 30 (while loop, matching the flowchart)2n = 03while n <= 30:4    print(n)5    n = n + 3

Expected output

Also correct — a for loopPython

1for n in range(0, 31, 3):2    print(n)

Expected output

Watch the end value: range(0, 30, 3) stops before 30, so 30 would be missing. The stop value must be 31 (anything above 30 and up to 33 works, but 31 is clearest). In the while loop, <= includes 30.