I typically don't answer numbers I don't know, but thought what the heck. The person mispronounced my name and I told him there was no one here by that name and then he apologized and said he had the wrong number. At least he was polite.
I don't answer calls from numbers I do not know. If something is important they will leave a message and I can call back. This policy has served me well to eliminate spammers.