I just need an explanation for both of these, please!

Answer:
See below.
Step-by-step explanation:
There are ten 'steps' over the dashes from 0 to 0.3 so he will walk another ten 'steps' to reach 0.6 miles.
So this will be at the beginning of the 20th dash.
1/2 a foot has 4 dashes in between the beginning and the end of 1111/2 ft.
3 / 1/2 = 6 so the mark will be at the end of the 4*6 = 24th dash.