Hey guys,

I don't want the answer to this I just want some help being able to explain this. I have just started doing graph theory in class, and haven't really figured out how to do the proofs yet. This problem just makes complete sense to me so its one of those that is hard to explain in a "proofy" way for me. Thanks for anyone's help in advance. The question is:

Let be a graph in which every vertex has degree at least . Show that there is a path of length at least k in G.