Margaret went to the hairdressers to get her hair washed, cut, dyed and styled. She was very pleased with the results! Her bill came to $85.00. How much should Margaret tip her hairdresser?

Some professions that provide you with personalized service don't pay well and so they expect a tip - waiters and waitresses, cab drivers, tour guides, hotel bell hops (yes they do still exist in many places), hotel maids, valet attendants (they park your car for you), movers and barbers and hair dressers.  
Often, tips are based on percentages.