Fie x distanta.
2x/9 - distanta din prima etapa
x-2x/9=7x/9 - restul
3/7*7x/9=3*7x/7*9=21x/63=x/3 - distanta parcursa in a doua etapa
7x/9-x/3=7x/9-3x/9=4x/9 - noul rest
3/8*4x/9=3*4x/8*9=12x/72=x/6 - distanta din a treia etapa
5/8*4x/9=5*4x/8*9=20x/72=5x/18 - restul drumului parcurs in a patra etapa
5x/18=50
5x=18*50
x=18*50/5
x=180 km
Drumul are 180 km.
Prima etapa: 2*180/9=40 km
A doua etapa: 180/3=60 km
A treia etapa: 180/6=30 km