It would take 60 hours for the rig to complete digging the -150 ft. hole.
Step-by-step explanation:
Hint: Using ratios will help solve questions like this one.
The first hole was dug -60 ft. below the surface for a whole day and night. A day lasts 12 hours and the same goes for a whole night. That's 24 hours in total. This will help answer Part A. A second hole was dug -150 ft. below the surface with the same rate as the first hole. Let's put this into a ratio.
-60 : 24
-150 : ?
Finding the scale factor in ratios will help solve for the missing value. We can divide -150 by -60 which results in 2.5. Multiply 2.5 by 24 and you will get 60 hours as your final answer. I hope you will find this helpful! :D