what type of math does google use to come up with page rank?programming?

This Wiki article might give you a very brief idea:

http://en.wikipedia.org/wiki/PageRank

The only two things anyone can definitively tell you about the algorithm Google uses in their pagerank is that it is extremely complex, and that it is extremely classified.

Google guards it with a level of secrecy rivaled only by the CIA and NSA. While I don't doubt they use all sorts of mathematical functions, no one is going to tell you for certain what kinds they use.