50 points!! pls help Mike, Joe, and Bill are painting a fence. The painting can be finished if Mike and Joe work together for 4 hours and Bill works alone for 2 hours, or if Mike and joe work together for 2 hours and Bill works alone for 5 hours, or if Mike works alone for 6 hours, Joe works alone for 2 hours and bill works alone for 1 hour. How much time does it take each man working alone to complete the painting?

pls, help I've asked multiple times to no avail. I've received multiple answers with no real steps on solving it. pls, include your steps on solving this problem so I am able to understand how you got your answer.