The forum at Novarata

I don't want to be at the bottom of a pile on for asking a silly question, but I was wondering what the tip would be for a cab trip that was 10 usd and another for 20 usd. I was figuring 1 and 2 bux respectively, but the cabbie wasn't acting like it was a big deal, so since I was doing a lot of repeat business for the day, I ran out of cash and started using the card. Turns out - upon inspection of my recent banking transactions that the 10 bux trip was rung in as 11 - so that explains why they weren't to concerned that I didn't hand them a 5 after every trip. There were 5 calls in all, in one day. I was using a cab company with a fleet of one.
So the question is - is 10% ok for 10 bux trip city cab fare

No clue.