Well it depends on what trail it is because they can can all be different lengths
6.
75(2) = 150
150(7) = 1060
1060 divided by 100 = $10.60
7. Add all the prices and you get $32 divide that by 2 and you get 16 hours
8. 2(8) = 16
1(3.5) =3.50
16+3.50=$19.50