A. The range of hours worked is the same for juniors and seniors.
Explanation: The range for juniors is 20 hours (20-0) and for seniors is also 20 hours (20-0), therefore the statement is true.
B. False: The mean, median, and mode for the juniors surveyed do not necessarily fall within a 3-hour range.
C. False: The mean number of hours worked by the seniors surveyed is not provided in the data.
D. False: The mean number of hours worked by juniors and seniors cannot be compared based on the data provided.