Practice neco computer_studies 2021 Past Questions

Question 1 View Details

For the following Python code, what is the output when $n = 10$?\n```\ncount = 0\nfor i in range(1, n+1):\n for j in range(1, i+1):\n if (i*j) % 3 == 0:\n count += 1\nprint(count)\n```

A. 26

Correct B. 27

C. 33

D. 30

Correct Answer: B

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Question 2 View Details

A parent <div> has a fixed width of 960px. The child <div> is styled with the following CSS:\n```css\n.child {\n width: 50%;\n padding: 10px 5%;\n border: 2px solid #000;\n box-sizing: content-box;\n}\n```\nWhat is the total rendered width of the child element in pixels?

A. 532

Correct B. 580

C. 576

D. 480

Correct Answer: B

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Question 3 View Details

A company purchases software licences as follows:\n- Type A: ₦12,000 each, quantity 25\n- Type B: ₦8,500 each, quantity 30\n- Type C: ₦5,750 each, quantity 20\nThe supplier offers a 10% discount on the total invoice if the subtotal exceeds ₦200,000, and an additional flat rebate of ₦15,000 if at least 20 licences of type A are bought. What is the final amount the company must pay?

A. 600000

B. 603000

Correct C. 588000

D. 573000

Correct Answer: C

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Question 4 View Details

A network administrator must subnet the address 192.168.0.0/24 for five departments that need 50, 30, 20, 10 and 5 usable host addresses respectively. Using VLSM and allocating the largest subnets first, what subnet mask (in dotted‑decimal notation) is assigned to the department that requires 30 hosts?

A. 255.255.255.128

B. 255.255.255.240

C. 255.255.255.192

Correct D. 255.255.255.224

Correct Answer: D

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Question 5 View Details

Consider the following HTML and CSS.\n```html\n<!DOCTYPE html>\n<html>\n<head>\n<style>\n p { color: blue; }\n .container p { color: green; }\n</style>\n</head>\n<body>\n<div class="container" style="color: red;">\n <p id="para">Sample text</p>\n</div>\n</body>\n</html>\n```\nWhat colour will the text of the paragraph with id "para" be displayed as in a standards‑compliant browser?

A. red

B. inherit

Correct C. green

D. blue

Correct Answer: C

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Question 6 View Details

The ENIAC was completed in 1945. The UNIVAC I was delivered 2 years later. The IBM System/360 was announced 15 years after the UNIVAC I. In what year was the IBM System/360 announced?

A. 1960

Correct B. 1962

C. 1970

D. 1963

Correct Answer: B

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Question 7 View Details

A webpage container has a fixed width of $1200\text{px}$. Inside it, a sidebar is set to $25\%$ of the container width, and the main content occupies the remaining horizontal space after accounting for a left and right margin of $30\text{px}$ each. The main content element uses `box-sizing: border-box` and has padding of $15\text{px}$ on each side and a border of $2\text{px}$ on each side. What is the width of the content area (the usable interior width) of the main content element in pixels?

A. 800

Correct B. 806

C. 822

D. 788

Correct Answer: B

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Question 8 View Details

A software vendor charges a base license fee of $\$150$ for the first user. For the next ten users (users 2 to 11) the fee is $\$45$ per user. For the following ten users (users 12 to 21) the fee is $\$40$ per user. Any additional user beyond the twenty‑first costs $\$35$ each. If a school has a budget of $\$1500$, what is the maximum number of user licenses it can purchase without exceeding the budget?

A. 33

B. 36

Correct C. 35

D. 34

Correct Answer: C

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Question 9 View Details

A hard‑drive is advertised as $500$ GB, where the manufacturer defines $1\text{ GB}=2^{30}$ bytes. The operating system reports capacities using the decimal definition $1\text{ GB}=10^{9}$ bytes. What capacity, in gigabytes to two decimal places, will the operating system display for this drive?

A. 536.86

Correct B. 536.87

C. 465.66

D. 537.00

Correct Answer: B

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Question 10 View Details

Consider a relation $R(A,B,C,D)$ with the functional dependencies $A \rightarrow B$, $BC \rightarrow D$, and $D \rightarrow A$. Determine the highest normal form (among 1NF, 2NF, 3NF, BCNF) that $R$ satisfies.

Correct A. 3NF

B. BCNF

C. 1NF

D. 2NF

Correct Answer: A

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Question 11 View Details

A video is recorded at a resolution of $1920 \times 1080$ pixels, 30 frames per second, with each pixel stored using 24 bits. The video is to be saved after compression that reduces the data size to 20% of the original. A 4 GB USB drive is to be used, but 10% of its capacity must be reserved for other files. What is the maximum whole number of seconds of video that can be stored on the drive?

A. 120

B. 110

Correct C. 103

D. 95

Correct Answer: C

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Question 12 View Details

A web page has a container whose total width is 1200 px. The container uses the standard box model with a padding of 20 px and a border of 5 px on each side. Inside the container there is a column set to a width of 30 % of the container's **content** width. The column itself has a padding of 10 px and a border of 2 px on each side.\n\n(a) What is the exact pixel width of the column's content area (excluding its own padding and border)?\n(b) If three such columns are placed side‑by‑side with a horizontal margin of 15 px between adjacent columns, will they fit within the container without overflow? If they fit, state the remaining horizontal space in pixels.

A. No, overflow by 12 px

B. Yes, 95 px remaining

Correct C. Yes, 85 px remaining

D. Yes, 70 px remaining

Correct Answer: C

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Question 13 View Details

Which computer component is primarily responsible for long‑term storage of data and retains information when the power is switched off?

A. Random‑access memory (RAM)

B. Optical disc (CD/DVD)

Correct C. Hard‑disk drive (HDD)

D. Solid‑state drive (SSD)

Correct Answer: C

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Question 14 View Details

An organization has been allocated the network address $192.168.64.0/22$. They need to create subnets that can each support at most 500 usable hosts. What is the smallest subnet mask they can use, and how many such subnets can be created from the original $/22$ network?

Correct A. /23, 2 subnets

B. /22, 1 subnet

C. /25, 8 subnets

D. /24, 4 subnets

Correct Answer: A

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Question 15 View Details

Who is widely recognised as the "father of the computer" for his design of the Analytical Engine?

A. Ada Lovelace

B. John von Neumann

Correct C. Charles Babbage

D. Alan Turing

Correct Answer: C

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Question 16 View Details

A 7‑bit Hamming code (positions 1,2,4 are parity bits) is transmitted using even parity. The received codeword is $1011110$. Determine the original 4‑bit data after correcting any single‑bit error.

A. 0010

B. 1000

Correct C. 1010

D. 1110

Correct Answer: C

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Question 17 View Details

A program counts the number of ordered pairs $(i,j)$ such that $1 \le i < j \le 20$ and $i + j$ is divisible by 4. What value does the program output?

A. 44

Correct B. 45

C. 40

D. 46

Correct Answer: B

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Question 18 View Details

In a spreadsheet, column B contains the unit price and column C the quantity sold. Write the formula for cell D2 that computes total sales applying a 10 % discount on the unit price when the quantity is at least 100, otherwise no discount. Then, using the data below, calculate the sum of total sales for rows 2 to 6. Row 2: Unit Price 250, Quantity 80 Row 3: Unit Price 150, Quantity 120 Row 4: Unit Price 300, Quantity 50 Row 5: Unit Price 200, Quantity 200 Row 6: Unit Price 400, Quantity 30

A. 94500

B. 105000

C. 100300

Correct D. 99200

Correct Answer: D

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Question 19 View Details

A software project follows the Waterfall model with five phases: Requirements, Design, Implementation, Testing and Maintenance. The total estimated effort is 1 200 person‑hours. Historically the effort distribution is 15 % Requirements, 25 % Design, 35 % Implementation, 20 % Testing and 5 % Maintenance. Due to a change request, the Design effort increases by 10 % of its original estimate and the Implementation effort decreases by 5 % of its original estimate. Re‑calculate the effort for each phase and the new total effort.

A. Requirements 180 h, Design 300 h, Implementation 399 h, Testing 240 h, Maintenance 60 h, Total 1179 h

B. Requirements 180 h, Design 330 h, Implementation 441 h, Testing 240 h, Maintenance 60 h, Total 1251 h

C. Requirements 180 h, Design 420 h, Implementation 360 h, Testing 240 h, Maintenance 60 h, Total 1260 h

Correct D. Requirements 180 h, Design 330 h, Implementation 399 h, Testing 240 h, Maintenance 60 h, Total 1209 h

Correct Answer: D

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Question 20 View Details

An organisation has been allocated the IPv4 block $192.168.64.0/22$. It needs subnets for three departments: Admin (50 hosts), HR (30 hosts) and IT (120 hosts). Using the smallest possible subnets for each department, list for each subnet the network address, broadcast address and usable host range. Also state any remaining address space.

A. IT: 192.168.64.0/25 (network 192.168.64.0, broadcast 192.168.64.128, hosts 192.168.64.1‑192.168.64.127); Admin: 192.168.64.128/26 (network 192.168.64.128, broadcast 192.168.64.192, hosts 192.168.64.129‑192.168.64.191); HR: 192.168.64.192/27 (network 192.168.64.192, broadcast 192.168.64.224, hosts 192.168.64.193‑192.168.64.223); Remaining: 192.168.64.225/27, 192.168.65.0/24, 192.168.66.0/24, 192.168.67.0/24]

B. IT: 192.168.64.0/24 (network 192.168.64.0, broadcast 192.168.64.255, hosts 192.168.64.1‑192.168.64.254); Admin: 192.168.65.0/26 (network 192.168.65.0, broadcast 192.168.65.63, hosts 192.168.65.1‑192.168.65.62); HR: 192.168.65.64/27 (network 192.168.65.64, broadcast 192.168.65.95, hosts 192.168.65.65‑192.168.65.94); Remaining: 192.168.65.96/27, 192.168.66.0/23]

Correct C. IT: 192.168.64.0/25 (network 192.168.64.0, broadcast 192.168.64.127, hosts 192.168.64.1‑192.168.64.126); Admin: 192.168.64.128/26 (network 192.168.64.128, broadcast 192.168.64.191, hosts 192.168.64.129‑192.168.64.190); HR: 192.168.64.192/27 (network 192.168.64.192, broadcast 192.168.64.223, hosts 192.168.64.193‑192.168.64.222); Remaining: 192.168.64.224/27, 192.168.65.0/24, 192.168.66.0/24, 192.168.67.0/24.

D. Admin: 192.168.64.0/26 (network 192.168.64.0, broadcast 192.168.64.63, hosts 192.168.64.1‑192.168.64.62); HR: 192.168.64.64/27 (network 192.168.64.64, broadcast 192.168.64.95, hosts 192.168.64.65‑192.168.64.94); IT: 192.168.64.96/25 (network 192.168.64.96, broadcast 192.168.64.223, hosts 192.168.64.97‑192.168.64.222); Remaining: 192.168.64.224/27, 192.168.65.0/24, 192.168.66.0/23]

Correct Answer: C

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Question 21 View Details

Given relation $R(A,B,C,D,E)$ with functional dependencies $A \rightarrow B$, $BC \rightarrow D$, $D \rightarrow E$, and $AB \rightarrow C$, (a) list all candidate keys, (b) state the highest normal form of $R$, and (c) decompose $R$ into BCNF relations, indicating whether the decomposition is lossless‑join and dependency‑preserving.

A. Candidate key: {A}. Highest normal form: BCNF. BCNF decomposition: R1(A,B) and R2(B,C,D,E); not lossless‑join and dependency‑preserving.

Correct B. Candidate key: {A}. Highest normal form: 1NF. BCNF decomposition: R1(B,C,D) and R2(A,B,C,E); lossless‑join but not dependency‑preserving.

C. Candidate key: {B,C}. Highest normal form: 3NF. BCNF decomposition: R1(A,B,C) and R2(C,D,E); lossless‑join but not dependency‑preserving.

D. Candidate key: {A,B}. Highest normal form: 2NF. BCNF decomposition: R1(A,B) and R2(B,C,D,E); lossless‑join and dependency‑preserving.

Correct Answer: B

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Question 22 View Details

An organization has been allocated the IPv4 network $192.168.48.0/20$. It needs subnets that can each accommodate at least 500 usable host addresses. (a) What subnet mask should be used? (b) How many such subnets can be created from the original network? (c) What is the first usable IP address in the 7th subnet (counting subnets from the first one)?

A. Subnet mask /22 (255.255.252.0). Number of subnets = 16. First usable IP of the 7th subnet = 192.168.52.1.

Correct B. Subnet mask /23 (255.255.254.0). Number of subnets = 8. First usable IP of the 7th subnet = 192.168.60.1.

C. Subnet mask /23 (255.255.254.0). Number of subnets = 6. First usable IP of the 7th subnet = 192.168.62.1.

D. Subnet mask /24 (255.255.255.0). Number of subnets = 4. First usable IP of the 7th subnet = 192.168.56.1.

Correct Answer: B

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Question 23 View Details

Consider the following Python code: ```python numbers = [12, 7, 5, 7, 3, 10, 5] total = 0 for i in range(len(numbers)): if numbers[i] % 2 == 1: for j in range(i+1, len(numbers)): if numbers[j] == numbers[i]: break else: total += numbers[i]**2 print(total) ``` What value is printed when the program is executed?

Correct A. 83

B. 49

C. 100

D. 58

Correct Answer: A

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Question 24 View Details

Which component of a computer system is primarily responsible for performing arithmetic and logical operations?

A. Random Access Memory (RAM)

Correct B. Central Processing Unit (CPU)

C. Motherboard (MB)

D. Graphics Processing Unit (GPU)

Correct Answer: B

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Question 25 View Details

A character is stored using 7‑bit ASCII as the binary string $0100101$. An odd‑parity bit is added as the most significant bit of the byte. (a) What is the resulting 8‑bit binary code? (b) What decimal value does this 8‑bit code represent?

Correct A. Binary code: 00100101; Decimal value: 37

B. Binary code: 01001011; Decimal value: 75

C. Binary code: 00100101; Decimal value: 45

D. Binary code: 10100101; Decimal value: 165

Correct Answer: A

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