Some things to think about... :) These could be things to answer for your two weekly postings!
1. Suppose a retailer promotes his or her store by advertising a drawing for a "free car". Is this car free because the winner pays zero for it?
2. Attending college is expensive, time-consuming, difficult, and requires effot. Why do people decide to go to college?
3. Give one positive and one normative statement for the same topic.
Unfortunately, most problems for PPC"s involve drawing, which...is difficult on here.
http://www.reffonomics.com/pp1.html an animated gif on the PPC. You'll see a lot from this guy.
AmosWEB - on PPC's -- http://www.amosweb.com/cgi-bin/awb_nav.pl?s=wpd&c=dsp&k=production+possibilities+curve
And...I think that's all I have tonight.