Quiz_3 1.jpg View Gallery

OK! Quiz: Can You Guess Who's Older? Test Your Knowledge of Eight Sets of Stars

How well do you know your favorite celebrities? Who's older: Demi Lovato or Selena Gomez? Adele or Kesha? Snooki or Kristen Stewart?

Photos: Pop Stars Who Have Guest Starred on TV Shows

Some stars seem older just because they've been around forever, while others are aging because they've been living the glamorous life a little too hard.

Photos: Showmance—TV Couples Dating for Real

Still, a lot of celebrities have the cutest little baby faces or they take really good care of themselves.

Photos: Celebrities Who Have Saved Lives

Click through OKMagazine.com's photo quiz and see how you do on guessing which star is older!

How did you do? Tell us in the comments section or on Twitter @OKMagazine

For access to all our exclusive celebrity videos and interviews – Subscribe on YouTube!

Sound off in the comments below!

Join the conversation