In a new video posted to Kourtney's app and website, the elder Karadshian sister and Khloé attempt to find the answer. The siblings play "Know Thy Sister," a trivia game similar to the Newlywed Game in which they each answer sister-specific questions and then compare answers.
As it turns out, the famous sisters know each other pretty well: Kourtney, 36, correctly guesses Khloé's favorite color (purple), the age when Khloé lost her virginity (15), Khloé's least favorite exercise (running on the treadmill) and which sister Khloé impersonates best (Kourtney, which Khloé demonstrates in a spot-on imitation).
For her part, Khloé, 31, thinks of Kourtney's least favorite exercise (spinning) before Kourtney figures it out herself, but she's stumped when asked about Kourtney's favorite color (black), favorite Disney movie (Peter Pan) and the age when she had her first kiss.
Head to Kourtney's website to watch the full video and brush up on your own Kardashian trivia skills.
Before posting the fun video, Kourtney shared a sweet photo on Instagram on Friday in which she gives daughter Penelope a piggyback ride in front of a bright piece of art at Los Angeles contemporary art museum The Broad.
"Murakami piggy back ride," she captioned the adorable pic.