ISTQB Advance Level CTAL-TTA Question # 1 Topic 1 Discussion

To achieve full Modified Condition/Decision Coverage (MC/DC), each condition within a decision must be shown to independently affect the outcome of the decision. For the decision IF X < 5 OR Y > 10 THEN, the conditions are:

Condition 1: X < 5

Condition 2: Y > 10

We need to test these conditions in such a way that each condition independently influences the decision outcome. Let's analyze the options:

Option A:

X=4 and Y=7 (X < 5 is true, Y > 10 is false; overall decision true)

X=6 and Y=12 (X < 5 is false, Y > 10 is true; overall decision true)

X=5 and Y=10 (X < 5 is false, Y > 10 is false; overall decision false)

This set achieves full MC/DC coverage because each condition is shown to independently affect the outcome.

Option B:

X=4 and Y=11 (X < 5 is true, Y > 10 is true; overall decision true)

X=7 and Y=10 (X < 5 is false, Y > 10 is false; overall decision false)

This set achieves full MC/DC coverage because it demonstrates both conditions independently affecting the outcome.

Option C:

X=5 and Y=8 (X < 5 is false, Y > 10 is false; overall decision false)

X=2 and Y=12 (X < 5 is true, Y > 10 is true; overall decision true)

X=4 and Y=4 (X < 5 is true, Y > 10 is false; overall decision true)

This set does not fully achieve MC/DC coverage as it does not demonstrate the impact of Y > 10 being false while X < 5 is false.

Option D:

X=3 and Y=10 (X < 5 is true, Y > 10 is false; overall decision true)

X=5 and Y=15 (X < 5 is false, Y > 10 is true; overall decision true)

X=0 and Y=15 (X < 5 is true, Y > 10 is true; overall decision true)

This set does not achieve MC/DC coverage because it does not show the decision outcome when both conditions are false.

Therefore, the correct answer is B. X=4 and Y=11, X=7 and Y=10.