ISTQB Foundation Level 4.0: 15 Questions with Answers

Are you preparing for the ISTQB Certified Tester Foundation Level 4.0 exam?

Or perhaps you already work in software testing and want to check how well you remember the most important testing concepts?

In this article, you will find 15 sample multiple-choice questions. Each question includes four answer options, the correct answer, and a short explanation.

The questions cover topics such as:

• fundamentals of software testing,
• the seven testing principles,
• static and dynamic testing,
• black-box and white-box test techniques,
• risk-based testing,
• test planning and monitoring,
• exploratory testing,
• test automation and test tools.

The questions are original and are based on the main knowledge areas covered in the current ISTQB CTFL 4.0 syllabus.

What does the ISTQB Foundation Level exam look like?

The ISTQB CTFL 4.0 exam consists of 40 questions.

You can score a maximum of 40 points, and you need at least 26 points to pass. The standard exam duration is 60 minutes.

The quiz below is shorter than the real exam, but it can help you quickly assess your knowledge and identify areas that may require additional study.

Write down your answers and check the explanations only after completing each question.

Question 1: Objectives of testing

Which answer best describes one of the main objectives of testing?

A. To prove that the software contains no defects
B. To guarantee that users will never experience a failure
C. To provide information about product quality and reduce risk
D. To find every possible defect before release

Correct answer: C

Testing helps evaluate product quality, detect failures, and provide stakeholders with information that supports decision-making.

However, testing cannot prove that software is completely defect-free or guarantee that failures will never occur.

Question 2: Exhaustive testing

Which testing principle explains why it is normally impossible to test every possible combination of inputs and conditions?

A. Testing is context dependent
B. Exhaustive testing is impossible
C. Defects cluster together
D. Tests lose effectiveness over time

Correct answer: B

The number of possible inputs, states, execution paths, and conditions is usually too large in real-world systems.

Instead of testing everything, testers must select test cases based on risk, priorities, and appropriate test techniques.

Question 3: Pesticide paradox

A team has been running the same regression test suite for several months. Over time, the tests stop finding new defects.

Which testing principle best describes this situation?

A. Defects cluster together
B. Testing shows the presence of defects, not their absence
C. Testing is context dependent
D. Repeated tests may lose their ability to detect new defects

Correct answer: D

Running the same tests with the same data repeatedly may cause the test suite to become less effective at finding new problems.

Tests should be regularly reviewed, updated, and expanded with new scenarios and test data. This phenomenon is often described as the pesticide paradox.

Question 4: Early testing

A team begins reviewing requirements before implementation starts.

What is one potential benefit of this approach?

A. System testing becomes unnecessary
B. Ambiguities and contradictions in the requirements can be detected early
C. It guarantees that the source code will contain no defects
D. It replaces all later testing activities

Correct answer: B

Early testing makes it possible to identify problems in requirements, designs, and other work products before source code is developed.

Defects found early are usually easier and less expensive to correct than defects discovered during later stages of development.

Question 5: Static testing

Which activity is an example of static testing?

A. Logging in with an incorrect password
B. Measuring application response time
C. Reviewing a requirements specification
D. Executing automated unit tests

Correct answer: C

Static testing does not require the software to be executed.

Examples include reviews of requirements, designs, test cases, and source code, as well as static analysis performed with specialized tools.

Question 6: Equivalence partitioning

An input field accepts an age between 18 and 65 inclusive.

How many basic equivalence partitions can be identified?

A. One
B. Two
C. Three
D. Four

Correct answer: C

Three basic equivalence partitions can be identified:

1. values below 18 — invalid partition,
2. values from 18 to 65 — valid partition,
3. values above 65 — invalid partition.

Equivalence partitioning assumes that values belonging to the same partition should be processed by the system in a similar way.

Question 7: Boundary value analysis

A field accepts a product quantity between 1 and 100 inclusive.

Which pair contains values directly outside the valid range?

A. 1 and 100
B. 2 and 99
C. 0 and 101
D. 50 and 51

Correct answer: C

The value 0 is directly below the lower boundary, while 101 is directly above the upper boundary.

Boundary value analysis focuses on values at and near boundaries because defects frequently occur in these areas.

Question 8: Decision table testing

An online store applies a discount when at least one of the following conditions is true:

• the customer is a member of the loyalty program,
• the order value is greater than $500.

How many basic combinations should a complete decision table contain?

A. Two
B. Three
C. Four
D. Eight

Correct answer: C

Each of the two conditions can be either true or false.

This produces four combinations:

1. the customer is not a member and the order value does not exceed $500,
2. the customer is a member and the order value does not exceed $500,
3. the customer is not a member and the order value exceeds $500,
4. the customer is a member and the order value exceeds $500.

Decision tables are particularly useful when testing business rules that depend on combinations of conditions.

Question 9: State transition testing

A user account is locked after the third consecutive failed login attempt.

Which scenario best tests the transition to the “account locked” state?

A. One successful login attempt
B. Two failed login attempts
C. Three consecutive failed login attempts
D. Logging out after a successful login

Correct answer: C

The system should transition to the “account locked” state after the third consecutive failed login attempt.

State transition testing examines system states, events, and the transitions caused by those events.

Question 10: Statement and branch coverage

Which statement about code coverage is correct?

A. Achieving 100% statement coverage always means achieving 100% branch coverage
B. Achieving 100% branch coverage also means achieving 100% statement coverage
C. Statement coverage and branch coverage always have the same value
D. Branch coverage is unrelated to the structure of the source code

Correct answer: B

Full branch coverage requires every possible outcome of each decision to be executed.

As a result, the statements inside those branches are also executed. Full statement coverage, however, does not necessarily mean that every possible decision outcome has been tested.

Question 11: Exploratory testing

In which situation can exploratory testing be particularly useful?

A. When testers must follow only predefined scripts step by step
B. When limited documentation is available and the tester has strong domain knowledge
C. When the system under test cannot be executed
D. When only automated regression testing is required

Correct answer: B

In exploratory testing, learning, test design, and test execution happen at the same time.

This approach can be especially useful when documentation is limited, quick feedback is needed, or the tester has significant experience and domain knowledge.

Question 12: Acceptance criteria

What is the main purpose of acceptance criteria for a user story?

A. To determine the project team’s compensation
B. To define the conditions that must be met for the user story to be accepted
C. To completely replace all test cases
D. To define the programming language used to build the application

Correct answer: B

Acceptance criteria describe the conditions that must be satisfied before the implementation of a user story can be accepted.

They help the team establish a shared understanding of the expected outcome and can be used as a basis for designing tests.

Question 13: Risk-based testing

A function in a banking system may incorrectly calculate charges for thousands of customers if it fails.

How should this information affect testing?

A. The function should receive a lower priority because it is complex
B. The function does not need to be tested if a developer has already checked it
C. The function should receive high priority and extensive testing
D. Only the visual appearance of the function should be tested

Correct answer: C

Testing priority should take product risk into account.

When the likelihood of failure or the potential impact is high, the affected area should be tested earlier and more thoroughly.

Question 14: Test monitoring

Which information can be used as a metric for monitoring testing progress?

A. Number of executed test cases
B. The tester’s favorite programming language
C. Number of meetings planned for the following year
D. The project manager’s computer model

Correct answer: A

Test monitoring may include information such as:

• number of planned and executed test cases,
• number of passed and failed tests,
• number of reported defects,
• level of test coverage,
• time spent on testing.

Metrics help teams evaluate progress and decide whether corrective actions are required.

Question 15: Test tools and automation

Which statement describes a potential risk related to test automation?

A. Automation always eliminates maintenance work
B. A tool automatically guarantees the quality of all test cases
C. The effort required to maintain test scripts and environments may be underestimated
D. Manual testing is no longer allowed after automation is introduced

Correct answer: C

Test automation can improve repeatability and speed up the execution of repetitive tests.

However, it also creates costs related to implementation, development, and maintenance. Test scripts must be updated when applications, interfaces, test data, or environments change.

Check your score

Award yourself one point for each correct answer.

13–15 points

Excellent result.

You understand the most important concepts and can apply them to practical scenarios. Before the exam, you should also complete full mock exams under realistic time limits.

10–12 points

You have a solid understanding of the fundamentals.

However, some areas still require review. Pay particular attention to the questions you answered incorrectly and revisit the relevant syllabus sections.

7–9 points

You already understand part of the exam material, but you need additional preparation.

Focus especially on test techniques, testing principles, and test management.

0–6 points

It would be helpful to review the fundamentals systematically.

Read the CTFL syllabus, learn the key definitions, and then complete additional practice questions.

How to prepare effectively for the ISTQB Foundation Level exam

Memorizing definitions alone may not be enough.

Many exam questions use short scenarios and require you to identify or apply the correct testing concept.

During your preparation:

1. Read the current CTFL syllabus.
2. Learn how to distinguish between similar terms.
3. Practice equivalence partitioning and boundary value analysis.
4. Answer scenario-based questions.
5. Read the explanations even when your answer is correct.
6. Complete full mock exams with a time limit.
7. Review the areas where you make the most mistakes.

Need more ISTQB practice questions?

If you are preparing for the exam and want to answer more questions, check out my ISTQB Foundation Level practice test course.

The course contains complete mock exams, correct answers, and detailed explanations.

You will learn not only which answer is correct, but also why the remaining options are incorrect.

The course can help you:

• assess your knowledge before the exam,
• review the most important exam topics,
• practice scenario-based questions,
• improve your time management,
• identify knowledge gaps,
• prepare more confidently for the CTFL exam.

Start preparing for the ISTQB Foundation Level exam today.

The questions in this article were created for educational purposes. They are not official ISTQB examination questions. ISTQB® is a registered trademark of the International Software Testing Qualifications Board.