Explanation / Rationale

a) Is correct. Since 100% statement coverage is achieved, every statement, including the ones with defects, must have been executed and evaluated at least once
b) Is not correct. Coverage depends on what is tested, not on the number of test cases. For example, for code “if (x==0) y=1”, one test case (x=0) achieves 100% statement coverage, but two test cases (x=1) and (x=2) together achieve only 50% statement coverage
c) Is not correct. If there is a loop in the code there may be an infinite number of possible paths, so it is not possible to execute all the possible paths in the code
d) Is not correct. Exhaustive testing is not possible (see the seven testing principles section in the syllabus). For example, for code “input x; print x” any single test with arbitrary x achieves 100% statement coverage, but covers one input value

Explanation / Rationale

a) Is not correct. Planning poker can estimate effort for a user story that is already written. It does not help in understanding what should be delivered
b) Is not correct. Reviews are not a collaborative user story writing practice
c) Is not correct. Iteration planning is a project-related practice, used to plan the work, not to understand what needs to be delivered
d) Is correct. Conversation explains how the software will be used and often allows the team to define meaningful acceptance criteria, thus obtaining a shared vision of what should be delivered

Explanation / Rationale

a) Is correct. This is something that can (and should) be checked before the code is submitted to version control
b) Is not correct. This is something that can be checked after step (2) is performed, because merge conflict reporting can be done after the code is submitted and merged
c) Is not correct. This fits better as the entry criterion for step (3)
d) Is not correct. This fits better as the exit criterion for step (3)

Explanation / Rationale

a) Is not correct. Component Test-Driven Development is not a correct example of a test-first approach to development
b) Is not correct. Integration Test-Driven Development is not a correct example of a test-first approach to development
c) Is not correct. System Test-Driven Development is not a correct example of a test-first approach to development
d) Is correct. Acceptance Test-Driven Development (ATDD) is a well-known example of a test-first approach to development

Explanation / Rationale

a) Is correct. Test automation can provide measures that are too complicated for humans to derive, such as white-box test coverage measures for all but the most trivial code
b) Is not correct. By using test tools the responsibility for the testing is NOT shared with the tool vendor as the vendor is not involved in the testing, and it is the tester’s responsibility. The only possible responsibility that could be assigned to the tool vendor is if the tool fails to work as expected and provides incorrect test results
c) Is not correct. Testers still need to perform critical thinking when analyzing anomalies in the test results to determine their likely cause
d) Is not correct. Neither testers nor tools can generate test cases simply from an analysis of the program code as the code is the implementation and provides no information on the expected results, which will need to come from another part of the test basis, such as the design specification

Explanation / Rationale

a) Is not correct. Most work products can be examined using some form of static testing, and a contract must be interpretable by humans and so could be reviewed, which is a form of static testing
b) Is not correct. Most work products can be examined using some form of static testing, and a test plan must be interpretable by humans and so could be reviewed, which is a form of static testing
c) Is correct. Most work products can be examined using some form of static testing; however it is not suitable for work products that are too complex for human interpretation and should not be analyzed by tools, and encrypted code is too complex for humans and if it is properly encrypted it will not be analyzable by most tools
d) Is not correct. Most work products can be examined using some form of static testing, and a test charter must be interpretable by humans and so could be reviewed, which is a form of static testing

Explanation / Rationale

a) Is not correct. Test execution and coverage tools facilitate the automated execution of test cases and the measurement of the coverage achieved by running those test cases. However, these tools do not help with the organization of defects and configuration management
b) Is not correct. Test design and implementation tools facilitate the generation of test cases, test data and test procedures, but they do not help with the organization of defects and configuration management
c) Is not correct. Defect management tools are used to manage defects but are not testing tools and are not used to organize test cases or configuration management
d) Is correct. Test management tools increase the test process efficiency by facilitating the management of the software development lifecycle (SDLC), requirements, tests, defects, and configuration management

Explanation / Rationale

In the three-point estimation technique:

E = (optimistic + 4*most likely + pessimistic)/6

E = (2+(4*11)+14)/6 = 10

Thus:
a) Is not correct
b) Is not correct
c) Is not correct
d) Is correct

Explanation / Rationale

Considering each of the listed benefits and drawbacks of the independence of testing:

i. Ideally, we want close collaboration between testers and developers, which is not increased by isolation. Thus, this is a disadvantage
ii. Testers and developers have varied backgrounds, technical viewpoints, and potential biases, allowing testers to usefully challenge assumptions made by stakeholders during system specification and implementation. Thus, this is an advantage
iii. The main disadvantage of independence in testing is that testers may become isolated from the development team, leading to communication problems, a lack of collaboration, and potentially an adversarial relationship, with testers being blamed for delays and bottlenecks in the release process. Thus, this is a disadvantage
iv. One of the disadvantages of independence in testing is that testers may become isolated from the development team, leading to developers feeling less accountable for quality. Thus, this is a disadvantage
v. The primary benefit of independence in testing is that testers are more likely to identify different types of failures and defects compared to developers, due to their varied backgrounds, technical viewpoints, and potential biases, including cognitive bias

Thus:
a) Is not correct
b) Is correct. The list entries showing benefits are ii and v
c) Is not correct
d) Is not correct

Explanation / Rationale

Test cases TC1, TC2, TC3 and TC4 cover, respectively, rules R2, R3, R7 and R6 in the decision table.
a) Is correct. The conditions “66-year-old”, “unregistered” and “no experience” match rule R4, which is not covered by the existing test cases, so after adding this test case, the decision table coverage will increase
b) Is not correct. The conditions “55-year-old”, “unregistered” and “2 years of experience” match rule R2, already covered by TC1. So adding this test case will not increase the coverage
c) Is not correct. The conditions “19-year-old”, “registered” and “5 years of experience” match rule R6, already covered by TC4. So adding this test case will not increase the coverage
d) Is not correct. The existing test cases cover only 4 out of 7 columns of the decision table. The coverage can be increased by adding test cases that cover yet uncovered columns, that is, R1, R4 and R5

Explanation / Rationale

a) Is not correct. Checklists should contain test conditions to be verified. This is an example of an error, not a test condition; even if the tester was able to deduce some potential test conditions from the examples of errors, this error description is too general
b) Is not correct. Checklists should not contain items that are better suited as exit criteria. This is an example of an exit criterion
c) Is not correct. Checklists should not contain items that are too general. This is a very general item, which practically describes the goal of testing
d) Is correct. This is an example of a test condition that can be checked by a human

Explanation / Rationale

The five listed descriptions and the corresponding review process activities are:

1. This describes part of the ‘communication and analysis’ activity
2. This describes part of the ‘fixing and reporting’ activity
3. This describes part of the ‘individual review’ activity
4. This describes part of the ‘planning’ activity
5. This describes part of the ‘review initiation’ activity

The generic review process from ISO/IEC 20246, which is outlined in the syllabus, comprises the following activities in this logical order:

• Planning (4)
• Review initiation (5)
• Individual review (3)
• Communication and analysis (1)
• Fixing and reporting (2)

Thus:
a) Is not correct
b) Is correct. The correct sequence of activities is: 4 – 5 – 3 – 1 – 2
c) Is not correct
d) Is not correct

Explanation / Rationale

Because TC1 and TC3 failed in Execution 1 (i.e., test (1) and test (3)), test (4) and test (6) are confirmation tests.
Because TC2 and TC3 failed in Execution 2 (i.e., tests (5) and (6)), test (8) and test (9) are also confirmation tests.
TC2 passed in Execution 1 (i.e., test (2)), so test (5) is a regression test.
TC1 passed in the Execution 2 (i.e., test (4)), so test (7) is also a regression test.
Thus:
a) Is not correct
b) Is correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. The test pyramid emphasizes having a larger number of tests at the lower test levels
b) Is correct. It is not true that near the top of pyramid, test automation should be more formal
c) Is not correct. Usually component testing and component integration testing are automated using API-based tools
d) Is not correct. For system testing and acceptance testing, the automated tests are typically created using GUI-based tools

Explanation / Rationale

a) Is not correct. Decision table testing is a black-box test technique, so it is specification-based, not structure-based – the test cases are not based on the decisions in the source code. In branch testing, the test cases are derived from knowledge of the control flow of the test object
b) Is not correct. Anticipation of potential defects is used in error guessing (an experience-based test technique), not in branch testing (a structure-based technique). In decision table testing, the test cases are derived from the specification that describes the business logic
c) Is not correct. If a test case is based on the knowledge of the control flow of the test object, it is a white-box test technique. Decision table testing is typically based on an analysis of business logic, so it is a black-box test technique. In branch testing, test cases are not derived from the specification – this would make it a black-box test technique. Branch testing is a white-box test technique, where test cases are derived based on the source code structure
d) Is correct. Decision table testing is a black-box test technique, so it is based on an analysis of the specified behavior of the test object without reference to its internal structure. Therefore, the test cases are independent of how the software is implemented. Branch testing is a white-box test technique, so test cases are based on an analysis of the test object’s internal structure and processing. As the test cases are dependent on how the software is designed and coded, they can only be created after the design or implementation of the test object

Explanation / Rationale

a) Is correct. Each test level has specific and distinct test objectives as a different form of test object (e.g., single component, complete system) is tested at each test level and overlapping test objectives would lead to unnecessary duplication
b) Is not correct. Test analysis and design for a given test level should start during the corresponding development phase to facilitate early testing (e.g., acceptance test analysis and design should begin during requirements analysis). Test implementation will generally start later, and test execution will start during the test level
c) Is not correct. Test design for a given test level should start during the corresponding development phase to facilitate early testing, however test design (e.g., test case generation) needs to be based on an agreed test basis, not an early draft, otherwise significant test effort may be wasted on creating test cases for a design that later changes
d) Is not correct. Quality control applies to all development activities, meaning that every software development activity has a corresponding test activity. However, the same symmetry does not apply to dynamic and static testing. There are some static testing activities (e.g., static analysis) for which there is no obvious corresponding dynamic testing activity

Explanation / Rationale

Considering each of the listed review types:

1. Technical review - This type of review is performed by technically qualified reviewers and led by a moderator. The objectives are to gain consensus and make decisions on technical problems while also evaluating quality and building confidence in the work product, generating new ideas, motivating and enabling authors to improve, and detecting anomalies
2. Informal review - The main objective is to detect anomalies. The process is not defined and does not require formal documented output
3. Inspection - This is the most formal review type, and it follows the complete generic review process. The primary objective is to find the most anomalies, and other objectives include evaluating quality and building confidence in the work product, motivating and enabling authors to improve, and collecting metrics that can be used to enhance the software development life cycle (SDLC), including the inspection process. The author cannot act as the review leader or scribe
4. Walkthrough - Led by the author, this type of review serves various objectives such as evaluating quality and building confidence in the work product, educating reviewers, gaining consensus, generating new ideas, motivating and enabling authors to improve, and detecting anomalies. Reviewers might perform an individual review before the walkthrough, but this is not mandatory

A. Includes objectives such as gaining consensus, generating new ideas, and motivating authors to improve (A)
B. The main objective is detecting potential defects and it generates no formal documented output (D)
C. The main objective is detecting potential defects and it requires metrics collection to support process improvement (C)
D. Includes objectives such as educating reviewers, gaining consensus, generating new ideas and detecting potential defects (B)

Thus:
a) Is not correct
b) Is correct. The correct match is: 1A, 2D, 3C, 4B
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is correct. The number of defects found is related to the test object quality
b) Is not correct. This is the measure of the test efficiency not the test object quality
c) Is not correct. The number of test cases executed does not tell us anything about the quality; test results might do
d) Is correct. defect density is related to the test object quality
e) Is not correct. Time to repair is a process metric. It does not tell us anything about the product quality

Explanation / Rationale

a) Is not correct. Strong communication skills, active listening, and teamwork abilities enable a tester to interact effectively with all stakeholders, however a deep knowledge of a variety of computer games that allowed them to get on well with one developer is not an example of a generic skill useful to testers
b) Is correct. Domain knowledge that can be used to understand and communicate with end-users and business representatives is one of the generic skills required by testers. A tester with experience as a pilot would make them better able to appreciate the acceptance criteria for the helicopter control system
c) Is not correct. Although programming skills could be considered as technical knowledge which can increase efficiency when utilizing some test tools, it is unlikely that these skills would improve their communication with business analysts
d) Is not correct. Although thoroughness, attention to detail, curiosity, and a methodical approach to identifying hard-to-find defects are all useful generic skills for testers, it is doubtful they would be generating test cases prior to starting exploratory testing. This is because one of the main tenets of exploratory testing is that the test cases are generated during the testing, not scripted in advance

Explanation / Rationale

The testware under consideration is a test charter

Test charters are the output from test design
Thus:
a) Is not correct
b) Is not correct
c) Is not correct
d) Is correct

Explanation / Rationale

Given the following description of test analysis:
To identify the features that require testing, the test basis is analyzed and defined as test conditions, which are then prioritized along with related risks. The systematic identification of test conditions as coverage items often involves using test techniques both during test analysis and as part of the test design activity.
From the above description, it can be seen that test techniques are often used in the test analysis and test design activities. Boundary value analysis and equivalence partitioning are test techniques.
a) Is not correct. Test implementation is not likely to involve the use of test techniques as it is mostly concerned with assembling test cases into test procedures, while test techniques create test cases
b) Is correct. Test design is likely to involve the use of test techniques to create test cases from test conditions and coverage items
c) Is not correct. Test execution is not likely to involve the use of test techniques as it is mostly concerned with executing test procedures (and so test cases), while test techniques create test cases
d) Is not correct. Test monitoring is not likely to involve the use of test techniques. Test monitoring is mostly concerned with ongoing checks to ensure the plan is being followed, while test techniques create test cases
e) Is correct. Test analysis is likely to involve the use of test techniques to identify test conditions

Explanation / Rationale

a) Is correct. This principle means that if the same tests are repeated over and over again, eventually these tests no longer find any new defects. This is probably why the tests all passed in this release as well
b) Is not correct. This principle says about the mistaken belief that just finding and fixing a large number of defects will ensure the success of a system
c) Is not correct. This principle says that a small number of components usually contain most of the defects
d) Is not correct. This principle states that testing all combinations of inputs and preconditions is not feasible

Explanation / Rationale

a) Is correct. For a complex configuration item (e.g., a test environment), CM records the items it consists of, their relationships, and versions
b) Is not correct. CM tools do not execute test cases and do not calculate coverage
c) Is not correct. A CM tool is not a license management tool
d) Is not correct. CM tools do not generate test data

Explanation / Rationale

a) Is not correct. The miscalculation of bonuses is a failure by the system, not a defect
b) Is not correct. The system not suitably supporting disabled users is a failure which eventually results in a fine, but the fine itself is not a failure (it appears to be the correct functioning of the regulatory system)
c) Is correct. The error is made by the programmer and this mistake is caused by them working under severe time pressure, which is the root cause of the subsequent defect
d) Is not correct. The poor design of the user interface, which does not suitably address disabled users, is a design defect caused by the designer error. Thus the design of the user interface includes a design defect not a designer error

Explanation / Rationale

a) Is not correct. Exploratory testing uses test charters, not a list of possible defects/failures. Although exploratory testing can incorporate the use of other test techniques, in this case fault attack is the most likely option
b) Is correct. This is a list of possible failures. Fault attacks are a methodical approach to the implementation of error guessing and require the tester to create or acquire a list of possible errors, defects and failures, and to design tests that will identify defects associated with the errors, expose the defects, or cause the failures
c) Is not correct. The tester is using a checklist of items to support their testing. Both error guessing and checklist-based testing use such lists, however, the list here is of possible failures, not test conditions, and so the MOST PROBABLE test technique is fault attack, which focuses on errors, defects and failures
d) Is not correct. BVA is based on an analysis of boundary values of equivalence partitions. The above list does not mention equivalence partitions or their boundaries

Explanation / Rationale

Risk assessment can use a quantitative or qualitative approach, or a mix of them. In the quantitative approach the risk level is calculated as the multiplication of risk likelihood and risk impact. So, Risk level = Risk likelihood * Risk impact
Then, Risk impact = Risk level / Risk likelihood.
In our case, Risk impact = $1,000 / 50% = $1,000 / 0.5 = $2,000.
Thus:
a) Is not correct
b) Is correct
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. The test automation approach is defined by testers with the help of developers and business representatives
b) Is not correct. The test strategy is decided in collaboration with the developers
c) Is not correct. Testers, developers, and business representatives are part of the whole team approach
d) Is correct. Testers will work closely with business representatives to ensure that the desired quality levels are achieved. This includes supporting and collaborating with them to help them create suitable acceptance tests

Explanation / Rationale

Considering each of the listed tool categories and their descriptions:

A. Static testing tools – support the tester in performing reviews and static analysis (4)
B. Tools supporting scalability and deployment standardization – For example, virtual machines, containerization tools (3)
C. DevOps tools – support the DevOps delivery pipeline, workflow tracking, automated build process(es), continuous integration/continuous delivery (CI/CD) (1)
D. Collaboration tools – facilitate communication (2)

Thus:
a) Is not correct
b) Is not correct
c) Is correct. The correct match is: 1C, 2D, 3B, 4A
d) Is not correct

Explanation / Rationale

a) Is not correct. Regression tests increase in number as the project progresses, as new regression tests are typically required as changes are made to the system. Similarly, the number of confirmation tests also typically increases as the project progresses as new confirmation tests are needed for each fix made to a system
b) Is not correct. It is the other way round. Confirmation tests are created and run when the test object is fixed, and regression tests are (ideally) run whenever the test object is enhanced (changed)
c) Is not correct. Confirmation testing verifies that a defect has been fixed correctly and so is concerned with testing changes to the test object. However, regression testing ensures that changes (including changes to the operational environment) do not have negative effects on unchanged software and so does not check that the operational environment remains unchanged
d) Is correct. Regression testing ensures that changes do not have negative effects on unchanged software. Confirmation testing verifies that a defect has been fixed – and so is concerned with changed code

Explanation / Rationale

a) Is not correct. Quality should be the responsibility of everyone working on the project and not the sole responsibility of the test team
b) Is not correct. First, it is not a benefit if an external test team does not meet delivery deadlines, and second, there is no reason to believe that external test teams will feel they do not have to meet strict delivery deadlines
c) Is not correct. It is bad practice for the test team to work in complete isolation, and we would expect an external test team to be concerned with changing project requirements and communicating well with developers
d) Is correct. Specifications are never perfect, meaning that assumptions will have to be made by the developer. An independent tester is useful in that they can challenge and verify the assumptions and subsequent interpretation made by the developer

Explanation / Rationale

There are three equivalence partitions: {..., 10, 11}, {12}, and {13, 14, ...}.
The boundary values are 11, 12 and 13. In the three-point boundary value analysis for each boundary, we need to test the boundary and both its neighbors, so:

• for 11 we test 10, 11, 12

• for 12 we test 11, 12, 13

• for 13 we test 12, 13, 14

Altogether we need to test 10, 11, 12, 13, and 14

Thus:
a) Is not correct
b) Is not correct
c) Is correct
d) Is not correct

Explanation / Rationale

a) Is correct. Debugging is the process of finding, analyzing, and removing the causes of failures in a component or system
b) Is not correct. Testing is the process concerned with planning, preparation and evaluation of a component or system and related work products to determine that they satisfy specified requirements, to demonstrate that they are fit for purpose and to detect defects. It is not related to fixing causes of failures
c) Is not correct. Requirement elicitation is the process of gathering, capturing, and consolidating requirements from available sources. It is not related to fixing causes of failures
d) Is not correct. Defect management is the process of recognizing, recording, classifying, investigating, resolving, and disposing of defects. It is not related to fixing causes of failures

Explanation / Rationale

The equivalence partitions are: {…, 99, 100}, {101, 102, …, 198, 199}, {200, 201, …}.
Thus, there are 4 boundary values, which are: 100, 101, 199 and 200.
In 2-value BVA, for each boundary value there are two coverage items (the boundary value and its closest neighbor belonging to the adjacent partition). As the closest neighbors are also boundary values in the adjacent partition, then there are just four coverage items.

Thus:
a) Is not correct. Only 100 and 200 are valid coverage items for 2-value BVA, so we achieve 50% coverage
b) Is not correct. Only 100 and 200 are valid coverage items for 2-value BVA, so we achieve 50% coverage
c) Is not correct. Only 100 and 101 are valid coverage items for 2-value BVA, so we achieve 50% coverage
d) Is correct. 101, 199 and 200 are valid coverage items for 2-value BVA, so we achieve 75% coverage

Explanation / Rationale

a) Is not correct. Testing quadrants group test levels and test types separately according to several criteria. They do not represent any combinations of test levels and test types and they are not related to any location within a software development lifecycle. Both test levels and test types are treated separately in the testing quadrants model
b) Is not correct. Testing quadrants group test levels and test types according to several criteria. They do not describe the degree of granularity of individual test types performed at each test level. Such a model, regarding the test levels, is called the test pyramid
c) Is not correct. The statement is wrong, because in general any test type can be performed at any test level
d) Is correct. The testing quadrants group test levels, test types, activities, test techniques and work products in Agile software development. In this model, tests can be business facing or technology facing. Tests can support the team (i.e., guide the development) or critique the product (i.e., measure its behavior against expectations). The combination of these two viewpoints determines the four quadrants

Explanation / Rationale

Considering each of the listed tool categories:

i. Collaboration tools – facilitate communication. Communication does not include the facilitation of test execution
ii. DevOps tools - support the DevOps delivery pipeline, workflow tracking, automated build process(es) and CI/CD. The delivery pipeline and CI/CD both include the facilitation of test execution, such as component testing for CI
iii. Management tools – increase the test process efficiency by facilitating management of the SDLC, requirements, tests, defects and configuration. The management of these items does not include the facilitation of test execution
iv. Non-functional testing tools – allow the tester to perform non-functional testing that is difficult or impossible to perform manually. Non-functional testing can include both static testing and dynamic testing, including test execution
v. Test design and implementation tools – facilitate generation of test cases, test data and test procedures. The generation of this testware does not include the facilitation of test execution

Thus:
a) Is not correct
b) Is correct. Both DevOps tools (ii) and Non-functional testing tools (iv) facilitate test execution
c) Is not correct
d) Is not correct

Explanation / Rationale

a) Is not correct. In all types of reviews there is more than one role, even in informal ones
b) Is correct. There are several activities during the formal review process
c) Is not correct. Documentation to be reviewed should be distributed as early as possible
d) Is not correct. Defects found during the review should be reported

Explanation / Rationale

a) Is correct. A fundamental strength that all white-box test techniques share is that the entire software implementation is taken into account during testing, which facilitates defect detection even when the software specification is vague, outdated or incomplete. This means white-box testing can find defects such as an extra feature added to the code (either accidentally or deliberately) that is not supposed to be there, which black-box testing cannot detect
b) Is not correct. The fact that the coverage can be precisely defined is not the right reason. The achieved level of coverage would have much more impact than the possibility to measure the coverage
c) Is not correct. If the software does not implement one or more requirements, white-box testing is unlikely to detect the resulting defects of omission
d) Is not correct. While this is true, this is not the right answer, because there is no connection between the capability to be used in both static testing and dynamic testing and the claim that white-box testing facilitates defect detection with poor specifications

Explanation / Rationale

a) Is not correct. This is a common characteristic of white-box test techniques. Test conditions, test cases, and test data are derived from a test basis that may include code, software architecture, detailed design, or any other source of information regarding the structure of the software.
b) Is not correct. This is a common characteristic of white-box test techniques. Coverage is measured based on the items tested within a selected structure and the technique applied to the test basis
c) Is correct. This is a common characteristic of experience-based test techniques. This knowledge and experience include expected use of the software, its environment, likely defects, and the distribution of those defects is used to define tests
d) Is not correct. This is a common characteristic of black-box test techniques. Test cases may be used to detect gaps within requirements and the implementation of the requirements, as well as deviations from the requirements

Explanation / Rationale

a) Is correct. The basic concept behind error guessing is that the tester tries to guess what errors may have been made by the developer and what defects may be in the test object based on past experience (and sometimes checklists)
b) Is not correct. Although a testers who used to be a developer may use their personal experience to help them when performing error guessing, the test technique is not based on prior knowledge of development
c) Is not correct. Error guessing is not a usability technique for guessing how users may fail to interact with the test object
d) Is not correct. Duplicating the development task has several flaws that make it impractical, such as the tester having equivalent skills to the developer and the time involved to perform the development. It is not error guessing

Explanation / Rationale

There are two equivalence partitions that are not yet covered, which correspond to “student discount” and “pensioner discount”.
a) Is not correct. CY – BY = 64, so these inputs correspond to the already covered “no discount” partition
b) Is correct. CY – BY = 65, so these inputs correspond to a partition that is not yet covered (“pensioner discount”)
c) Is not correct. CY – BY = –65, so these inputs correspond to the already covered “error message” partition
d) Is not correct. CY – BY = 18, so these inputs correspond to the already covered “no discount” partition
e) Is correct. CY – BY = 0, so these inputs correspond to a partition that is not yet covered (“student discount”)