dialog between me and my staff: Staff : boss, how old are you? Me : Guess? Staff : 26?? Me : hahahaha.... thank you thank you Staff : how old are you??? Me : secret!!!
There is a fountain of youth: it is your mind, your talents, the creativity you bring to your life and the lives of people you love. When you learn to tap this source, you will truly have defeated age.
몇 살이야? (informal) 나이가 어떻게 되세요? (formal) *notice : if you ask 너, 몇 살이야? to someone, you will need to fight with him/her. To avoid fight, this way is better to ask age. 몇 살이에요? or 나이가 어떻게 되세요? also if you ask age to kids, you can use this 몇 살이니?
(Korean)
en serio?? 
