<human>:  Some friends went hiking for 3.5 hours. They traveled 21 kilometers in that time. Birgit was 4 minutes/km faster than the average time. If Birgit kept the same pace, how many minutes would it take her to go 8 kilometers?
<bot>: How many minutes were spent hiking? ** Minutes spent hiking = 3.5*60 = <<3.5*60=210>>210 minutes
What was the average speed in minutes/km? ** Average speed = 210 minutes/ 21 km = <<210/21=10>>10 minutes/km
How fast is Birgit in minutes/km? ** Birgit is 4 minutes/km faster = 10 - 4 = 6 min/km
How many minutes would it take Birgit to go 8 kilometers? ** It would take 6*8 = <<6*8=48>>48 minutes to go 8 km
How many minutes would it take Birgit to go 8 kilometers? ** Birgit would take 48 minutes to travel 8 kilometers.
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