1. Introduction
This question evaluates how much 2-value Boundary Value Analysis (BVA) coverage is achieved for a grading system based on point ranges.
본 문제는 점수 구간에 따른 학점 시스템에서 현재 테스트 케이스가 2값 경계값 분석(BVA)을 얼마나 충족하는지를 묻는 문제입니다.
2. Final Grade Rules
Grades are assigned as follows:
| Range | Grade |
|---|---|
| 0–50 | failed |
| 51–60 | fair |
| 61–70 | satisfactory |
| 71–80 | good |
| 81–90 | very good |
| 91–100 | excellent |
3. Test Cases Provided
| Test Case | Final Result | Expected Grade |
|---|---|---|
| TC1 | 91 | excellent |
| TC2 | 50 | failed |
| TC3 | 81 | very good |
| TC4 | 60 | fair |
| TC5 | 70 | satisfactory |
| TC6 | 80 | good |
4. Boundary Value Analysis
✔ 2-value BVA Boundary Points
Each range boundary produces two boundary values: the boundary itself and the next value (either +1 or –1 depending on direction).
All boundaries (12 total):
0, 50, 51, 60, 61, 70, 71, 80, 81, 90, 91, 100
총 12개의 2값 경계값이 존재합니다.
✔ Coverage from existing test cases
Current test cases cover these boundary points:
- 50 (TC2)
- 60 (TC4)
- 70 (TC5)
- 80 (TC6)
- 81 (TC3)
- 91 (TC1)
→ 6 out of 12 boundaries covered
→ 50% coverage
테스트 케이스가 12개의 경계 중 6개를 커버하므로 커버리지는 50%입니다.
5. Correct Answer
✅ Correct Answer: a) 50%
📘 Explanation (EN/KR)
- There are 12 total BVA boundary values.
- The existing tests cover 6 of them.
- Therefore: 6 / 12 = 50%.
총 12개 경계 중 6개만 테스트되었으므로 커버리지는 정확히 50% → 정답은 (a)
6. Final Summary
- 2-value BVA checks boundaries and their immediate neighbors.
- This grading system produces 12 such boundary values.
- Current tests cover exactly half of them.
경계값을 정확히 나누면 계산이 매우 쉬워지는 문제 유형입니다.
FL-4.2.2
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