Răspuns:
[tex]\boldsymbol{ \red{60 \ km}}[/tex]
Explicație pas cu pas:
[tex]|\underbrace{---|---}_{T}|\underbrace{---}_{B}|\underbrace{---}_{15}|[/tex]
Notăm cu x lungimea traseului.
[tex]x = \dfrac{x}{2} + \dfrac{1}{2} \cdot \bigg(x - \dfrac{x}{2}\bigg) + 15[/tex]
[tex]x = \dfrac{x}{2} + \dfrac{x}{2} - \dfrac{x}{4} + 15[/tex]
[tex]x = x - \dfrac{x}{4} + 15[/tex]
[tex]\dfrac{x}{4} = 15 \Rightarrow x = 4 \cdot 15[/tex]
[tex]\Rightarrow x = 60[/tex]
R: 60 km
