[tex]\boxed{v=\frac{d}{t}} \\\\ v_{med.1}=(\frac{20 \ km}{1 \ h}+\frac{40 \ km}{2 \ h}+\frac{60 \ km}{3 \ h}+\frac{80 \ km}{4 \ h}+\frac{80 \ km}{5 \ h})/5 \\ v_{med.1}=\frac{20 \ km/h+20 \ km/h+20 \ km/h+20 \ km/h+16 \ km/h}{5}=\frac{96 \ km/h}{5} ; \\ \Rightarrow \boxed{\bold{v_{med.1}=19,2 \ km/h}} \\ \\ v_{med.2}=(\frac{30 \ km}{1 \ h}+\frac{50 \ km}{2 \ h}+\frac{60 \ km}{3 \ h}+\frac{40 \ km}{4 \ h}+\frac{30 \ km}{5 \ h})/5 [/tex]
[tex]v_{med.2}=\frac{30 \ km/h+25 \ km/h+20 \ km/h+10 \ km/h+6 \ km/h}{5}=\frac{91 \ km/h}{5} ; \\ \Rightarrow \boxed{\bold{v_{med.2}=18,2 \ km/h}}[/tex]
