I never answer either, unless I recognize the number. However, I did get into a very ornery mood one day and decided to pick up and play along--by playing young and dumb. After every question, I'd answer with something that made no sense. For example,
Him: Is this so-and so?
Me: I like broccoli.
Him: Pardon me, ma'am. Are you so-and-so?
Me: My uncle is a dentist. Do you floss your teeth?
Him: No, ma'am, but we are calling because there is a probably with your Microsoft computer and we would like to help. We just need a little information.
Me: My microwave works fine. What's your dog's name?
I carried on till they asked if my mommy was home. I said, "I don't know. You'll have to call her."
Just about couldn't keep from laughing , so thankfully he hung up.