Depends on how fast you walk.
15-20 minutes approx at average walking speed
half a second if you walk fast
It depends on how fast you walk. A typical (high end) walking rate is about 6 km/h, so 40 km would take 6 2/3 hours at that rate.
A couple of hours.
For a normally fit and heathly person, about 10 minutes - you should be able to walk 3km in an hour, 1km in 20 minutes and so half a KM in about 10. If it's raining probably longer though
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