Blonde Joke - Sheep (13)
A blonde is sitting at home one day when she decides she's sick of hearing blonde jokes. She decides to dye her hair brown, and, to see if it works in making her more intelligent, goes to a farm where she approaches the farmer with the challenge, "If I can guess how many sheep you have, can I take one home?" The farmer chuckles to himself, before replying, "Sure, why not?"
The blonde pulls out a calculator and does a bunch of hugely complicated equations and comes up with a number. She says to the farmer, "There are 314 sheep out there." The farmer is astonished. "You're right!" he says. "Go take your pick".
The blonde takes a few minutes to pick a sheep, waves to the farmer, and leaves.
She's sitting at home the next day when she hears a knock on her front door. She opens it and finds the farmer standing there holding his hat. He says to her, "If I can guess your real hair colour, can I have my dog back?"