Hello!
10 km in 2.5h.
2,5h = 150mn
150mn -> 10km
1 mn -> 10/150
60mn -> (10*60)/150
=>4km/h
Jason ran 7.5 km in 2h.
7,5 /2 =3,75
=> 3,75km/h
Olga ran 9.5 km in 2.25h.
2,25h = 120 + 0,25 * 60 =>135mn
135mn -> 9,5km
1mn -> 9,5/ 135
60mn -> (9,5*60)/ 135 =>4,22km/h
Who had the fastest average speed.: Olga