conversations.from: human
conversations.value: James loves to go swimming and has to swim across a 20-mile lake.  He can swim at a pace of 2 miles per hour.  He swims 60% of the distance.  After that, he stops on an island and rests for half as long as the swimming time.  He then finishes the remaining distance while going half the speed.  How long did it take him to get across the lake?
  Give me a clear explanation.
conversations.from: assistant
conversations.value: He swam 20*.6=12 miles.
  That took him 12/2=6 hours.
  So he rested 6/2=3 hours.
  He then swam the remaining 20-12=8 miles.
  His pace was 2/2=1 mph.
  So it took him 8/1=8 hours.
  So in total, he took 6+3+8=17 hours.