Combinatorics BOB

It is again time for Blogging on Blogging since it is the end of the unit. I would have to say that this unit was probably the most difficult of the others we've done. I had a bit of a problem trying to solve the card questions like one of the ones we did for the pretest we had today. I used (13C1)(12C1) for the 2 pair question instead of (13C2). I know the rules for Combinatorics, but there were times I had trouble applying them to some problems because I was worried I was wrong and second guessed myself. I'm glad, though, that the questions we did for the pretest were ones I probably had more trouble on.