A test score indicator for students produces a performance score based on a combination of the number of consecutive hours studied (below 4 hours, 4 to 8 hours. 9 to 12 hours or above 12 hours) and the average intensity of focus on the material during the study time (low, medium or high).
Given the following test cases:
hours intensity score
T1 3 low55
T2 14 high 95
T3 9 low75
What is the minimum number of additional test cases that are needed to ensure full coverage of all valid INPUT equivalence partitions?