Hope this helps...
Basically, do you notice the pattern?
The amount of minutes taken is the amount of kilometres plus half the amount of kilometres.
Ok, so
For 2km 2÷2=1 2+1=3km
For 1km 1÷2=½ 1+½=1½
For 5km 5÷2=2½ 5+2½=7½
For 2 minutes, 1⅓km.
TBS, 1⅓÷2=0.66666...
1⅓+0.66666....=2.
