2.BC is 250 meters away from the starting point and stays for 5 minutes.
Point A means 10 minutes to 450 meters.
Point D means start 16 minutes, and return to the starting point.
3. Make up one for yourself, what Xiaoming forgot to bring something halfway and ran back.
(Pay attention to time and distance)
Update 1: Not every copy must be the same.
That means: cut one knife: 2+2 cut two knives: 4+4 cut three knives: 8+6 cut four knives: 14+8 cut five knives: 22+ 1