Merge order = 6 (number of SORTWK files that can be merged simultaneously) - After pass 1: 40 runs merged 6 at a time = ceil(40/6) = 7 runs - After pass 2: 7 runs merged 6 at a time = ceil(7/6) = 2 runs - After pass 3: 2 runs merged = 1 final sorted output - Total merge passes = **3**