Question

Suppose you have three test cases:

➢ Test 1 gives you 20% decision coverage.
➢ Test 2 gives you 30% decision coverage.
➢ Test 3 gives you 30% decision coverage.
What is the possible decision coverage that can be achieved by a test suite consisted only of these three tests?
A. 82%
B. 50%
C. 25%
D. 1.8%

Answer 1

Option (B), The maximum possible decision coverage combining three tests with coverage of 20%, 30%, and 30% is 80%, assuming no overlap. However, considering potential overlaps, the coverage may be less. Given the options, the closest is 50%.

Step-by-step explanation:

The student's question pertains to calculating the possible decision coverage that can be achieved by a test suite consisted only of three given tests with specified decision coverage percentages. To find the combined coverage, let's assume that each test covers different parts of the decision space. Thus, we would add up the coverage percentages, but since there might be some overlap, the actual total coverage could be less than the sum of individual coverages.

However, the question seems to be asking for the highest possible coverage without considering overlap. If we simply add the individual coverages (20% + 30% + 30%), we get 80%. Since no combination options are given between 50% and 82%, it's safe to assume that the overlap does not allow for a higher coverage than 80%. Therefore, the closest correct option provided would be:

• B. 50%