Eric took 20 hours to do the job alone.
<u>Step-by-step explanation</u>:
<u>Given </u>:
- Total work = 75 packages
- Joe took 5 hours to complete the total work.
The amount of work Joe alone can do per hour = 75/5 = 15 packages.
The amount of work Joe and Eric together do per hour = 75/4 = 18.75
The amount of work Eric alone can do per hour = 18.75 - 15 = 3.75
The time Eric took to complete the entire work = 75 / 3.75 = 20 hours.
The area of the inscribed triangle = 3(6^2 x sin 120°) = 3(36sin 120°) = 3(31.18) = 93.53 square in.
Down, the line is going down