question: John decides to get a loan by mortgaging his home.  His house is worth $250,000.  He gets a loan worth 40% of that.  He uses 60% of that to pay off his debts.  How much money did he have leftover after paying debt?
answer: His loan is worth 250,000*.4=$<<250000*.4=100000>>100,000
  That means he uses 100,000*.6=$<<100000*.6=60000>>60,000 to pay off debts
  So he has 100,000-60,000=$<<100000-60000=40000>>40,000 leftover
  #### 40,000