Examples:

• How old are you and what's your name?
• How old are you and your sister?
• How old are you, if you don't mind?
• Tell me the truth. How old are you?
• How old are you two, may I ask?
• You need to tell us, katie. How old are you?
• How old are you that you still act like this?
• How old are you, Mr. Ji?
• How old are you, Miss Turner?
• How old are you, if I may ask?