x - lungimea drumului
I zi = x/3
II zi = 1/3 (x - x/3) +16 =1 /3 x 2x/3 +16 = 2x/9 +16
x/3 + 2x/9 + 16 +36 = x
x/3 + 2x/9 + 52 = x /x9
3x + 2x + 468 = 9x
5x + 468 =9x
468 = 9x - 5x
468 = 4x
x= 468 : 4
x=117
Drumul are 117 km
I zi a parcurs: 117 x 1/3 = 39 km
a II zi a parcurs: 2 x 117/9 +16 = 26 +16 = 42 km
39/42 = aprox. 0,9285 = 92,85%