question: Gary bought a boat for $9000.  Over the first year it depreciated 30%.  The second year it depreciated another 30%.  The third year it depreciated 20%.  How much is the boat worth after the three years?
answer: After first year:9000(.30)=2700
  9000-2700=<<9000-2700=6300>>6300
  After second year:6300(.30)=1890
  6300-1890=<<6300-1890=4410>>4410
  After third year:4410(.20)=882
  4410-882=<<4410-882=3528>>3528$
  #### 3528