x-lungimea drumului
I zi: x-35x/100=(100x-35x)/100=65x/100=13x/20
II zi: 13x/20-(13x/20)·20/100=13x/20-13x/100=
(65x-13)/100=52x/100=26x/50=13x/25
34x/25=624
34x=624·25
x=15600/13
x=1200 km
I zi a parcurs 1200x35/100=420km
II zi: (1200-420)x20/100=156km
420+156+624=1200