Answer :

To get the answer we have to add 7 4/5km and 10 3/5
[tex]7 \frac{4}{5} + 10\frac{3}{5}=7+10+ \frac{4}{5} + \frac{3}{5} =17+ \frac{4+3}{5}=17+ \frac{7}{2}= 17 +1 \frac{2}{5} =18 \frac{2}{5} [/tex] - its the result