First Jamie wants to figure out how many calories his father needs to lose from 5 pounds x 3500 calories each = <<5*3500=17500>>17,500 calories to burn off.
Then Jamie needs to figure out how many calories his father will burn per day if he burns 2500 calories - eating 2000 calories = burning <<2500-2000=500>>500 calories a day.
If Jamie's father wants to burn off 17,500 calories total at 500 calories a day, 17,500 / 500 = <<17500/500=35>>35 days to burn off 5 pounds.
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