I've seen this one used in an Introduction to Psychology exam: http://xkcd.com/32/ http://xkcd.com/32/ And the velociraptor problem was a class exercise for cal

I've seen this one used in an Introduction to Psychology exam: http://xkcd.com/32/ http://xkcd.com/32/ And the velociraptor problem was a class exercise for calculus: http://www.xkcd.com/135/ http://www.xkcd.com/135/