conversations.from: human
conversations.value: Find a solution for this math problem: John buys 500 newspapers.  Each newspaper sells for $2.  He sells 80% of them.  He buys them all for 75% less than the price at which he sells them.  How much profit does he make?
conversations.from: assistant
conversations.value: He sells 500*.8=400 newspapers
  He sells them for 400*2=$800
  He gets a discount of 2*.75=$1.5 on the newspapers
  So he buys them for 2-1.5=$.5
  So he spent 500*.5=$250 buying them
  That means he made a profit of 800-250=$550