question: John decides to do several activities while out on vacation.  He spends 6 hours boating and half that time swimming.  He also watched 3 different shows which were 2 hours each.  This was 30% of the time he spent.  He spent 40% of his time sightseeing.  How much time did he spend sightseeing?
answer: He spent 6/2=<<6/2=3>>3 hours swimming
  He spent 3*2=<<3*2=6>>6 hours watching shows
  So he spent 6+3+6=<<6+3+6=15>>15 hours on these activities
  That means he spent 15/.3=<<15/.3=50>>50 hours on activities
  So he spent 50*.4=<<50*.4=20>>20 hours sightseeing
  #### 20