Miss Utah -- RIDDLE TIME ... And She Kinda Nails It???

She already (kinda) redeemed herself for that infamous pageant flub -- so yesterday, we decided to pelt the beautiful Miss Utah with some brain-twisting riddles instead ... and she actually did pretty damn well.

21-year-old Marissa Powell had just touched down in L.A. for her appearance on "Jimmy Kimmel Live" -- and while she was at the airport, we asked her a bunch of questions to test her wits on the fly ... such as the classic "Who is buried in Grant's tomb?" and "What can you put in a bucket of water to make it lighter?"

She doesn't exactly get them right, but she doesn't exactly get them wrong either. Then again, she could probably say anything and we'd be happy.