Answer:
-37.5 m
Step-by-step explanation:
If we assume that "one full day" is 24 hours, then 15 hours represents the fraction 15/24 of a day. Since the drilling rate was constant, and was presumed to start from a height of 0, the height after 15 hours is that fraction of the day's work:
... (15/24)×(-60 m) = -37.5 m
