Zippos.com is an online shoe retail store. While most customers shop online at the company’s Internet site, many others call the company directly for specialized assistance with questions. After phone operators are first hired and trained they spend an average of 24 minutes talking to a customer, much of which is taken up with the new phone operators looking up answers to questions they don’t know off -hand on the company’s website. If phone operators have an 85% learning curve while learning typical responses to customer questions, how many calls will they have to experience until they can reduce their call time to 10 minutes?