A dumb blonde was really tired of being made fun of, so she decided to have her hair she would look like a brunette. 

When she had brown hair, she decided to take a drive in the country. 

After she had been driving for a while, she saw a farmer and a flock of sheep and thought,  

"Oh! Those sheep are so adorable!" 

She got out and walked over to the farmer and said,  

"If I can guess how many sheep you have, can I take one home?" 

The farmer, being a bit of a gambler himself, said she could have a try. 

The blonde looked at the flock and guessed, "157." 

The farmer was amazed - she was right! So the blonde, (who looked like a brunette), picked one out and got back into her car. 

Before she left, farmer walked up to her and said.  

"If I can guess the real color of your hair, can I have my dog back?"