Mr. & Mrs. Summer hired movers to move their furniture to their new home. It took 3 movers a total of 8 hours to move all of the furniture. How much in total should the movers receive for a tip?

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.