Calling all Economics experts

[MTK]

Here's what I came up with.

For the printers its $20/20 books = 1. Simple enough, my professor agrees with this answer.

Here's where it gets messy. For the presses I again did the wage/rate and got $5000/1000 = 5. Seems to make sense to me, but my professor says it's 50/100 = .5.

I have no clue where he's getting this from, and he's horrible at explaining things.

Here's my ultimate dilemma though. I have to present this answer, and others, tomorrow night in class. Should I present his answer, or mine?? If I present his answer and someone calls me out on it, I'm gonna have no clue what to say. I'm pretty sure his answer is wrong. I guess I'm just going to present his answers and if someone asks I'll just defer to him.