human
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?
assistant
How many miles does Peter have left to walk? ** Peter has to walk a remaining 2.5 total miles - 1 mile completed = <<2.5-1=1.5>>1.5 miles remaining
How many minutes does Peter have left to walk? ** It will take him another 20 minutes * 1.5 miles remaining = <<20*1.5=30>>30 minutes to get to the grocery store
#### 30