✦ YORIMICHI RESEARCH LABORATORY / AP LAB
AP × AI LEARNING EXPERIMENT

ROUND 5
Questions 041–050

Think first. Then reveal the answer and reasoning.
Ten questions to turn technical terms into understanding.

How to use this page

Choose one answer (A–D) for each question. When ready, click “Show Answer & Explanation” below it. Click again to hide the explanation. Answers are hidden by default.

These are the same ten questions used in the learning experiment. Each explanation also records the original participant response.

QUESTION 041Networking

When visiting a website from an office computer, what is the primary role of a DNS server?

  1. A. Encrypt network communications
  2. B. Map domain names to IP addresses
  3. C. Automatically remove viruses
  4. D. Keep page display speed constant
Show Answer & Explanation +

Correct answer: B — Map domain names to IP addresses

DNS maps website names (domain names) to IP addresses used to reach the destination. Think of it as the internet’s phone book.

Learning experiment response: B / Correct

QUESTION 042Security

Opening an attachment from a received email caused malicious software to run. Which preventive measure is most appropriate?

  1. A. Check the sender and contents before opening attachments
  2. B. Automatically forward every email
  3. C. Share passwords with everyone
  4. D. Set the computer clock every day
Show Answer & Explanation +

Correct answer: A — Check the sender and contents before opening attachments

Verify the sender and the attachment, and do not open suspicious files. Attackers may impersonate someone you know.

Learning experiment response: A / Correct

QUESTION 043Databases

You want to link a customer table and an orders table using their shared customer ID, then display the names of customers who placed orders. Which SQL operation is primarily used?

  1. A. GROUP BY
  2. B. ORDER BY
  3. C. JOIN
  4. D. DELETE
Show Answer & Explanation +

Correct answer: C — JOIN

JOIN combines tables using a common key. GROUP BY groups rows, ORDER BY sorts rows, and DELETE removes rows.

Learning experiment response: C / Correct

QUESTION 044Algorithms

What is the most efficient way to calculate the sum of the integers from 1 through 100?

  1. A. Multiply all numbers from 1 through 100
  2. B. Add 100 to itself 100 times
  3. C. Add only the odd numbers
  4. D. Calculate 100 × 101 ÷ 2
Show Answer & Explanation +

Correct answer: D — Calculate 100 × 101 ÷ 2

The sum is 100 × 101 ÷ 2 = 5,050. The formula gives the answer directly. Option B would give 10,000.

Learning experiment response: B / Review needed

QUESTION 045System Reliability

Device A and device B each have 99% availability. They are connected in series, so the system works only when both devices work. Assuming independent failures, approximately what is the overall availability?

  1. A. 99.99%
  2. B. 98.01%
  3. C. 99%
  4. D. 50%
Show Answer & Explanation +

Correct answer: B — 98.01%

In a series system, both devices must work: 0.99 × 0.99 = 0.9801, or 98.01%.

Learning experiment response: B / Correct

QUESTION 046Cloud Computing

Which example represents Software as a Service (SaaS)?

  1. A. A user purchases a physical server
  2. B. A user manufactures a CPU
  3. C. A user accesses ready-to-use business software over the internet
  4. D. A user constructs a data-center building
Show Answer & Explanation +

Correct answer: C — A user accesses ready-to-use business software over the internet

SaaS stands for Software as a Service. It provides ready-to-use software over the internet.

Learning experiment response: D / Review needed

QUESTION 047Project Management

If a certain task is delayed, the entire project completion date is delayed. What is the name of the path containing such tasks?

  1. A. Critical path
  2. B. Backup route
  3. C. Firewall
  4. D. Access path
Show Answer & Explanation +

Correct answer: A — Critical path

The critical path is the sequence of tasks with no scheduling slack; delays on this path delay project completion.

Learning experiment response: A / Correct

QUESTION 048AI & Machine Learning

When training an AI model on historical stock prices, future data is accidentally included in the training data. What is this problem called?

  1. A. Load balancing
  2. B. Normalization
  3. C. Encryption
  4. D. Data leakage
Show Answer & Explanation +

Correct answer: D — Data leakage

Using future information in training or evaluation can produce unrealistically high performance that cannot be reproduced in real trading. This is especially important in stock-market backtesting.

Learning experiment response: A / Review needed

QUESTION 049 Information Security

What is a primary purpose of a digital signature?

  1. A. Increase communication speed
  2. B. Verify the signer and detect data tampering
  3. C. Reduce file size
  4. D. Make all information confidential
Show Answer & Explanation +

Correct answer: B — Verify the signer and detect data tampering

Digital signatures help verify who signed the data and whether the signed data has been altered.

Learning experiment response: B / Correct

QUESTION 050 Software Testing

Which testing approach checks whether a program meets specifications by examining inputs and outputs without inspecting its internal structure?

  1. A. White-box testing
  2. B. Static analysis
  3. C. Black-box testing
  4. D. Code review
Show Answer & Explanation +

Correct answer: C — Black-box testing

Black-box testing compares inputs and expected outputs without examining the internal implementation. White-box testing examines internal logic.

Learning experiment response: B / Review needed

ROUND 5 | Progress at 50 Questions

6 / 10 correct (60%)

Strengths: DNS, email safety, SQL JOIN, availability calculations, critical path, and digital signatures.

Review topics: arithmetic series, SaaS, data leakage, and black-box testing.

Next focus: Can I explain each term using a concrete example, rather than simply recognize the word?

These are original practice questions created for learning, not official past examination questions.