conversations.from: human
conversations.value: Mike decides to develop a plot of land.  He bought 200 acres for $70 per acre.  After development, he sold half of the acreage for $200 per acre.  How much profit did he make?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: He bought the land for 200*70=$14000
  He sold 200/2=100 acres
  He got 100*200=$20,000 from selling this
  So he made a profit of 20,000-14,000=$6,000