When the drill reaches a depth of -915 feet or lower, scientists have to add a special liquid to prevent
 5
 the hole from freezing over. If the research team drills – 50 feet per day, how many days will it take
 6
 to reach a depth of -915 feet?
 V
 What is a reasonable estimate for the number of days?
 200 days
 50 days
 20 days
 5 days
 _915 -1,000 -50% -50
 -1,000 = (-50) = ?