###Human: James buys 2 puzzles that are 2000 pieces each.  He anticipates for these larger puzzles he can do 100 pieces every 10 minutes.  So how long would it take to finish both puzzles?, ### Assistant: His speed means he can do 10/100=.1 minute per piece
So he can finish 1 puzzle in 2000*.1=200 minutes
So these two puzzles take 200*2=400 minutes 
 So the answer is :  400