This joke is INSULTING!!!

Three blondes are stuck on a desert island and one finds a magic lamp. They rub it and a genie pops out and gives them each a wish. the first blonde says, "I wish I was 10% smarter so I could get off of this island." Then she turns into a redhead and swims off the island. The second sees what happens and says "I wish I was 25% smarter so that I can get off this island!" She then turns into a brunette, makes a raft from trees and sails off. Finally, the third blonde says "I wish I was 50% smarter so I can get off this island." She then suddenly turns into a man and walks across the bridge.