I'm a woman in my mid-twenties, and I recently started a new job where most of my co-workers and the people we serve are 10-20 years older than I am. I have no problem with that arrangement, except that on an almost daily basis, someone asks me my age. How should I respond?
Younger than You
Putting aside the fact that this is totally inappropriate for almost any scenario within a work environment, you're faced with the dilemma of having to respond to a stupid question. You have two options: You can tell them your age or you cannot tell them your age. How you respond is much more important than what you ultimately say, and as long as you remain fully respectful and professional, almost any response you provide would be acceptable.
I tend to think full disclosure is best, especially because if you don't share your age, you're likely to keep getting the question, and if you tell even one or two people, word may get around, and you won't have to keep responding. You could try looking the person square in the eye, saying, "Twenty-five" with no emotional response, and then moving on to whatever the work-related matter at hand might be. If you sheepishly say the same number, you leave more room for additional responses. Also, if someone picks up on an inkling that you're self-conscious of your age, you're in a much more vulnerable position to be treated as young. If you confidently state the answer with no apology and then move on, there's not much more for anyone to say without edging into territory that you can either ignore or respond to by saying, "I'm not comfortable sharing my personal life at work."
If you really feel as though sharing your age is to be avoided at all costs, you can try saying, "Older than you think," or, "Old enough to have my degree," or even a terribly old-fashioned, "That's not something ladies discuss." If you say, "I prefer not to tell you," you come across as unnecessarily evasive. (Again, I've already acknowledged that it's a stupid thing to be asked, but once someone asks, you win by taking the high road.) Try to avoid snarky responses or sarcasm, which will only make you seem younger and less professional. Also make sure your facebook profile settings won't allow just anyone to see your year of birth.
The other option is to lie. Pick an age that you think won't elicit, "You're so young!" responses but that is also believeable given your appearance and what else is known about you at work (graduation year, for example), and tell people that. I don't think this is a great idea and you're likely to be uncovered as a liar at some point, but if you can't find another solution that feels workable, you could try this out. Depending on what communication is like in your office, you could try many different responses from all of the above options for a couple of weeks and see what provides you with the most satisfactory results, then stick with that. Depending on how long this goes on, eventually, you'll be another year older anyway, and then another year older after that, and the looks and the questions will diminish to the point where, believe it or not, you may look back wistfully at this inconvenience.