Ignore them. This is the easiest thing to do when dealing with these type of people. They will always think they are right or they will not care to listen to you because they don't want to be wrong...even if they know you're right.

(Many people are like this on this site lol.)

Focus on something else. This will help you ignore the person who is bothering you.

(Ya right!)

If they persist in arguing with you calmly tell them you aren't going to argue with them.

(In all reailty who isn't going to argue back?)

The reason I posted this, lol, is because I think it's funny that someone actually hate to post how to ignore ignorant people. Everyone is ignorant in some way lol.