question: John fills a 6 foot by 4 foot pool that is 5 feet deep.  It cost $.1 per cubic foot to fill.  How much does it cost to fill?
answer: The pool has a base of 6*4=<<6*4=24>>24 square feet
  So its volume was 24*5=<<24*5=120>>120 cubic feet
  So it cost 120*.1=$<<120*.1=12>>12 to fill the pool
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