Order matters or not

Hi damit,

This is a good question, but PLEASE don't get too wrapped up in all this combinations stuff over a problem like this. The order doesn't matter, because when you grab two books, then who cares what order you hold them in. The question would have to be more specific in order for order to matter.

Since there are only 6 books, I would just chart it out and leave the formulas at home:

a-b
a-c
a-d
a-e
a-f

and

b-c
b-d
b-e
b-f

That's nine. I didn't do b-a here, because we did it already in the first one, so that's the only place where order makes a difference anyway. If the question doesn't include the one instance where you get both, then you can elliminate it anyway, so the answer is 8. I'm not sure which one this is by the wording.

Hope that helps!