Question

Forty laps around a track is equals 2.5 km. How far is one lap around the track?

and,

A wheel makes 1 turn in 0.7 second. What part of a turn can it make in 0.35 second?

Answer 1

I believe this is the way to do your first question 

If 40 laps around the track is 2.5 km you would divide 2.5km by 40 laps and get 0.0625 km