|---------| prima zi
|---------|-----------| + 18, a treia zi
daca a livrat in a treia zi cu 25 t mai mult decat in a doua zi, in a doua zi a livrat 2 segmente +18-25= 2 segmente -7
|---------|----------| - 7 a doua zi
61-18+7=50
5 segmente=50
50:5= 10 tone 1 segment
prima zi 10 tone
a doua zi 2*10-7=13 tone
a treia zi 2*10+18=38 tone