x=lungime drum
x/2 -10 =ziua 1
x-(x/2-10)=x/2+10 =rest
0,2(x/2+10)+15=x/10+2+15=x/10+17=ziua 2
22,6 km=ziua 3
x/2 -10+x/10+17+22,6=x
x/2 +x/10+29,6=x
5x+x+296=10x
4x=296
x=74 km
ziua 1 74/2-10=37-10=27 km
74-27=47 km
ziua 2 47 ×0,2 +15=9,4+15=24,4 km
ziua 3 74-27-24,4=22,6 km