human
John decides to replace all his VHS with DVDs. He can trade in his VHS for $2 each and then buy the DVDs for $10 each. If he has 100 movies, how much does it cost to replace his movies?
assistant
How much does it cost to replace each movie? ** It cost 10-2=$<<10-2=8>>8 to replace each movie
How much does it cost to replace everything? ** So it would cost 8*100=$<<8*100=800>>800 to replace everything
#### 800