Barbie enters the beauty salon and, without saying a word, sits in a salon chair. Ken, her stylist, washes and cuts her hair. Thereafter, Barbie rises from the salon chair and ken informs her that she owes him $$40$ for the wash and cut. Barbie refuses to pay, claiming there cannot be a contract because she never verbally agreed to pay Ken. Explain whether there is a contract between Barbie and Ken.