Contract Formation: Question 1

Bill is looking to purchase a set of outlines for first-year law school subjects when he begins law school. His friend Ted, who has just graduated from law school, has a set of first year outlines he is looking to get rid of. He gives them to Bill and says, "Take a look at these and see if they will be helpful to you. If you want to buy them, just write me a check for \$50." Bill thanks Ted. He never verbally responds to Ted's offer, but he uses the outlines throughout his first year of law school, marking them up with notes and highlights. He also loans them to other first-year students in his study group. Toward the end of Bill's first year, Ted contacts him and asks for payment for the outlines. Bill refuses. If Ted sues Bill for breach of contract, what result?