MCQ Retake Review

This notebook includes the question setup for each missed problem along with the correction, the reasoning, and the mistake I need to avoid on the retake.

1. Game Piece / Counter Problem

A game piece moves left or right depending on the color of the space:

  • Yellow -> move 3 left
  • Black -> move 1 left
  • Green -> move 2 right

A counter increases each time the piece moves. The game starts on the rightmost black space and ends when the piece lands on red or leaves the board.

Question
What is the final value of the counter?
  • Chosen answer: B (3)
  • Correct answer: 4
  • Why this is wrong: The counter increments after every move, not just certain moves.
  • Correct reasoning:
    • Black -> move 1 left -> counter = 1
    • Yellow -> move 3 left -> counter = 2
    • Green -> move 2 right -> counter = 3
    • Green -> move 2 right -> lands on red -> counter = 4
  • Core mistake: The full sequence of moves was not completed.

2. Network Communication Problem

Devices are connected in a network. If devices are not directly connected, communication must pass through others.

Question
Which statement is true about the network?

Statement D: “If devices C and F fail, then device D will not be able to communicate with device H.”

  • Chosen answer: D (false)
  • Correct answer: D is not correct because the claim inside D is false.
  • Why this is wrong: Even if C and F fail, communication is still possible.
  • Correct reasoning: An alternate path exists: D -> B -> E -> H
  • Core mistake: Failure to check all possible communication paths.

3. MOD Code Problem

A list is processed with:

result <- result + (item MOD 2)

Question
What value is displayed?
  • Chosen answer: B (4)
  • Correct answer: 3
  • Why this is wrong: item MOD 2 does not count even numbers.
  • Correct reasoning:
    • Even -> MOD 2 = 0
    • Odd -> MOD 2 = 1
  • So the program counts odd numbers.
  • List: [4, 2, 5, 4, 2, 3, 1]
  • Odd values: 5, 3, 1 -> total = 3
  • Core mistake: Misinterpreting MOD as counting evens.

4. Keylogging Question

Question
Which scenario best represents keylogging used to gain unauthorized access?
  • Chosen answer: D (phishing example)
  • Correct answer: A
  • Why this is wrong: Choice D describes phishing, not keylogging.
  • Correct reasoning: Keylogging means recording keystrokes without awareness. Choice A describes software capturing all input and sending it elsewhere.
  • Core mistake: Confusing different cybersecurity attack types.

5. Robot Movement Problem

A robot follows a path using a procedure:

botStepper(n): move n rotate left move n rotate right

Question
Which code reaches the target square?
  • Chosen answer: A
  • Why this is wrong: The robot does not reach the final square.
  • Correct reasoning: After executing both calls in A, the robot stops one square short of the goal.
  • Core mistake: The final position was not verified precisely.

6. Spreadsheet Filtering and Sorting

Three operations:

  • Filter by number of ratings
  • Filter by payment type
  • Sort by rating
Question
Which sequences correctly identify the top restaurant?
  • Chosen answer: B
  • Correct answer: D (all sequences)
  • Why this is wrong: All three sequences work.
  • Correct reasoning: Filtering does not change order, so sorting can happen before or after filtering.
  • Core mistake: Incorrect assumption that order matters.

7. Boolean Expression (Restaurant Criteria)

A restaurant must:

  • Have rating >= 4.0
  • Have price “lo” or “med”
Question
Which expression evaluates to true correctly?
  • Chosen answer: C
  • Correct answer: B
  • Why this is wrong: Choice C uses OR incorrectly.
  • Correct reasoning: Both conditions must be satisfied:
    • (avgRating >= 4.0) AND ((prcRange = “lo”) OR (prcRange = “med”))
  • Core mistake: Using OR when both conditions are required.

A sorted list has 128 elements.

Question
What is the maximum number of elements examined in a binary search?
  • Chosen answer: C (64)
  • Correct answer: 8
  • Why this is wrong: Binary search does not examine half the list one-by-one.
  • Correct reasoning: Binary search uses logarithmic steps.
    • log2(128) = 7 -> about 8 checks max
  • Core mistake: Confusion between eliminated elements and steps taken.

9. Algorithm Completion (Counting occurrences)

An algorithm counts how many times a target appears in a list.

Question
Which steps correctly complete the algorithm?
  • Chosen answer: D
  • Correct answer: A
  • Why this is wrong: Condition “repeat until count > n” is impossible.
  • Correct reasoning: Loop should continue until all positions are checked:
    • Repeat until position > n
  • Core mistake: Using an impossible stopping condition.

10. Data Privacy Concern

A fitness app tracks user location and suggests routes.

Question
What is the most likely privacy concern?
  • Chosen answer: A
  • Correct answer: B
  • Why this is wrong: Carrying a phone is not a privacy issue.
  • Correct reasoning: Choice B allows others to infer user locations -> privacy risk.
  • Core mistake: Confusing inconvenience with privacy.

11. Logic Table

A truth table is given.

Question
Which expressions match the table? (Select two)
  • Chosen answer: B
  • Correct answers: A and D
  • Why this is wrong: Choice B does not match all cases.
  • Correct reasoning:
    • The table is false only when both inputs are true.
    • Equivalent expressions:
      • NOT (input1 AND input2)
      • (NOT input1) OR (NOT input2)
  • Core mistake: Insufficient testing of all truth table cases.

Overall Patterns

  • I need to slow down on simulation problems and follow each step to completion.
  • I need to test alternate paths, edge cases, and multiple truth table rows instead of trusting a first impression.
  • I need to be more precise with core definitions like MOD, privacy, phishing, and keylogging.