Mick and Kelly are deciding how to split their time between writing music and lyrics for their new album. Their PPFs for 72 hours of work are shown below. . Mick and Kelly have to write music for 8 songs and lyrics for 12 songs (4 songs already have music). When they are done, they can go to a private island and relax from all their hard work. It is possible that they will use more than 72 hours.
Once they start writing lyrics and music, assuming their hired help packs for them and their plane is waiting outside their door, in how many hours can they board the plane to their relaxing island getaway?