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We’ve heard of starting with a bang, but Olga Fonda (Nadia) entered the world of The Vampire Diaries with a triple bang, if you catch our drift. That’s right, in the Season 5 premiere of TVD last fall, the ravishing Russian actress was introduced as having had a scandalous threesome with Matt (Zach Roerig) and Rebekah (Claire Holt).

Since then it’s been revealed that she’s the long-lost daughter of Katherine Pierce (Nina Dobrev), we got a little curious about just how old the Eastern European import is in relation to her on-screen mother.

During last Thursday’s all-new episode of The Vampire Diaries, Wetpaint asked Viggle users how old they think Olga is, either 25, 28, or 31 years old. And the results are in!

Care to test your knowledge of The Vampire Diaries with other questions about the hit show? Download Viggle now!

Only 16 percent of Viggle users thought Olga was 25 — the same age as Nina — while 38 percent guessed that she was only slightly older at 28. Shockingly, both of these are wrong, leaving the majority of Viggle users, 46 percent, to correctly guessed that Olga is 31 years old.

We think Olga looks absolutely stunning and could pass as a much younger gal, which is quite handy since she is six years older than her on-screen mom. Granted, Nadia is a Traveler and her mom is a Petrova doppelganger vampire, which means age is pretty relative when you’re almost 500 years old.

Do you want to test your TV knowledge? Not only is it easy, but you also get rewarded just for watching your favorite shows! All you have to do is download the Viggle app, get watching, and check into Viggle LIVE!

Carson Blackwelder is an Assistant Editor at Wetpaint Entertainment. Follow him on Twitter and Google+!