Q: How many earth ponies do you need to fill an oil lamp?
A1 (Applejack): Jist one, an' don't ya try tellin' me Ah need help!
A2 (Pinkie): Two; one to fill the lamp, and one to throw a lamp-filling party!
A3: C'nt shp'k n', mm m'ths f'll.
Q: ... pegasus ponies?
A1 (Rainbow Dash): Just one, but they'll be AWESOME at it!
A2 (Fluttershy): Um. I...I can do it myself, I don't want to be a bother...
A3 (Derpy): That depends on how big the lamp and the pegasi are!
Q: ... unicorns?
A1 (Twilight): One, obviously. ... Wait, this is an oil lamp joke, right? Ooh, I've got a whole book of them somewhere!
A2 (Rarity): An oil lamp? Darling, they're so last season! Every fashionable pony has switched to fairy lights!
A3 (Trixie): The Great and Powerful Trixie will AMAZE and ASTOUND you with her wondrous lamp-filling skills! BEHOLD!
Q: ... rock farmers?
A: We don't use fancy new-fangled things like oil lamps, young lady!
Q: ... Diamond Dogs?
A: Three, to capture a unicorn to do it for them.
Q: ... Lunar cultists?
A: None. They want the night to last forever!
Q: ... Griffons?
A: You ponies think it's funny to tell jokes about us, huh? Screw you losers, I'm outta here.
Q: ... Dragons?
A: Only one, but he'll only get around to it after napping for a century.