A few _floss readers have requested a Mensa-test-level challenge, so as a card-carrying member, I'm more than happy to oblige. This one, I think, is pretty darned difficult.

What's the final letter in this sequence?

B, G, L, S, ...?

HERE'S the answer.

THE ANSWER: The letter "Z." The sequence takes the first letter past the first vowel (A > B), then the second letter past the second vowel (E > F > G), and so the final entry is the fifth letter past the fifth vowel (U > V > W > X > Y > Z).