question: Carl buys ten packs of cookies. Each pack of cookies has six cookies inside. Each cookie cost $0.10. How much change does Carl receive if he pay with a $10 bill?
answer: A pack of cookies costs 6 x $0.10 = $<<6*0.1=0.60>>0.60.
  Thus, ten packs of cookies cost 10 x $0.6 = $<<10*0.6=6>>6.
  Therefore, Carl will receive a $10 - $6 = $<<10-6=4>>4 change.
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