Let's see how this works with an example,
"What is your name?"
Answer truthfully: Tyler
Answer untruthfully: McDonaldson
Don't answer, but explain truthfully: I won't tell you my name because I don't want to talk to you.
Don't answer but explain untruthfully: I won't tell you my name because I swore an oath never to never tell it.
Delay/ignore the question: I'm hungry
The way someone chooses to respond says something about that person or their feelings about the question. Choosing to respond with a none answer usually means the person wasn't paying attention or doesn't know how to communicate well. Another example,
"Can you spare some change?"
Answer truthfully: Yes, but you can't have any
Answer untruthfully: No, sorry
Don't answer, but explain truthfully: I might, but it doesn't matter because I don't give money away.
Don't answer but explain untruthfully: I might, but I can't spare any.
Delay/ignore the question: (look away and walk by)
Opinions on addressing unsolicited questions from strangers vary, but when you're with friends and family, at least offer an opinion when asked a question. It's such a waste of breath to poll people for their opinion when they don't
care enough about their own tastes or future to weigh in.
Some people excuse it by saying they're "laid-back", or "open to many options". What it really means is they want you to do the work of making the decision or are too insecure to share what they think. If you're really that much of a free-spirit without opinions and desires-- get some.
Half the the time the person that says they "don't care" will then speak up as to why he/she doesn't like the ideas offered by others. A final example,
"Where should we eat?"
Answer truthfully: I want pizza!
Answer untruthfully: I want scrapple!
Don't answer, but explain truthfully: I can't pick. I'm torn between pizza and chinese.
Don't answer but explain untruthfully: I can't pick. Someone put a curse on me and I can't make decisions today.
Delay/ignore the question: Whatever, I don't care.
Me: Let's get scrapple
Them: I don't like scrapple
Me: What do you like?
Them: Anything, just not scrapple
Them: Not that either
Them: That sounds good, but what about pizza?
Me: (Having just wasted 10 seconds of my life and x brainpower) Pizza sounds good to me
Of course, people who ask open-ended questions all the time are just as bad. They're pro-active in moving things forward but indecisive. The best way to avoid the hassle: "Want to get scrapple or do you have something else in mind?"