Here each drove is 12 hours.
[tex]\begin{gathered} \text{Rate }\times\text{ Time=Distance} \\ Late\text{ Vlado rate =R} \\ \text{ and Santi rate = 75R} \\ \text{ Total distance }=\text{ santi'rate }\times time\text{ driving +}Valado^{\prime}s\text{ rate}\times time\text{ driving} \end{gathered}[/tex]