question: Twenty dozen cups cost $1200 less than the total cost of half a dozen plates sold at $6000 each. Calculate the total cost of buying each cup.
answer: Since a dozen has 12 items, half a dozen plates are 12/2 = <<6=6>>6
  Half a dozen plates sold at $6000 each cost 6*$6000 = $<<6*6000=36000>>36000
  Twenty dozen cups cost $1200 less than the total cost of half a dozen plates, meaning the twenty dozen cups cost a total of $36000-$1200 = 34800
  Since a dozen has 12 items, twenty dozen cups are 20*12 = <<20*12=240>>240 cups.
  If the twenty dozen cups cost $34800, each cup costs $34800/240=$<<34800/240=145>>145
  #### 145