Peter has to walk 2.5 miles to get to the grocery store. If it takes him 20 minutes to walk one mile and he has walked 1 mile already, how many more minutes does he have to walk to reach it?
Peter has to walk a remaining 2.5 total miles - 1 mile completed = <<2.5-1=1.5>>1.5 miles remaining
It will take him another 20 minutes * 1.5 miles remaining = <<20*1.5=30>>30 minutes to get to the grocery store
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