Answer
1⁄4 (10,000 - 100)
Work Step by Step
If the machine can sort 100 names in one second, it can perform 1⁄4 (10,000 - 100) comparisons in one second.
This means that each comparison takes approximately 0.0004 seconds. Consequently, sorting 1000 names [which requires an average of 1⁄4 (1,000,000 - 1000) comparisons] requires roughly 100 seconds or 1 2⁄3 minutes.
