I have 2
10.4
14.0

I have three that I carry with me: AmEx, MasterCard and Visa but I'm not sure what the current rates on them are. I haven't been carrying a balance on them lately.

I also have a few others that I almost never use.

I have five credit cards, but I only use 2 of them and I am about to cut up the rest. I don't think that you should have more than one credit card personally.

Years ago when I travelled for work, my reasoning for having different kinds of cards was to hopefully be able to pay for any unexpected car towing or repair bill, regardless of which kind of card the service station accepted.