The courts have ruled that it is a reasonable restraint of trade

(and therefore permissible) for the owner of a business to sell his business and sign a contract with the new owner saying he will not compete with her within a vicinity of, say, 100 miles, for a period of, say, 5 years. If this is a reasonable restraint of trade, can you give an example of what you would consider an unreasonable restraint of trade? Explain how you decide what is a reasonable restraint of trade and what isn’t.