human
John drinks a bottle of water every half hour. A normal sudoku puzzle takes him 45 minutes. An extreme sudoku takes 4 times that long. How many bottles of water does he drink in that time?
assistant
How many bottles of water does John drink in a half hour? ** He drinks a bottle of water every 60/2=<<60/2=30>>30 minutes
How many minutes does it take John to solve an extreme sudoku? ** It takes him 45*4=<<45*4=180>>180 minutes to solve an extreme sudoku
How many bottles of water does John drink in a half hour? ** So he drinks 180/30=<<180/30=6>>6 bottles in that time
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