There once was a blonde who had two horses, but she couldn't tell them
apart. So she goes to her friend and says, "I have two horses and I just
can't tell them apart."
The friend suggested that she cut off one's mane. The blonde did, but
the mane grew back. She goes to her friend again, and the friend
suggested she cut off one of the horses' tails. The blonde did, but the
tail grew back too fast. So she finally says to her friend, "I've tried
all of your suggestions, but it just doesn't work."
The friend suggests one more thing, that she measure them. The blonde
went home, got a ruler, measured them, and went to her friend the next
morning.
The blonde tells her friend, "Oh, thank you! I can tell them apart!"
"How?" asked the friend.
The blonde tells her, "The black horse is taller than the white horse!"
