Réponse :
Explications étape par étape
Bjr,
1)
20 tr/s => 20*60 => 1200tr/mn
2)
1500tr/mn => 1500/60 =>25tr/s
3)
4m -> 67,50
1m -> 67,50/4
7m -> (67,50 *7)/4 =>118,13€
4)
105km -> 75mn
1km -> 75/105
189 km -> (75*189)/105 => 135mn -> 2h 15mn
5)
80km/h
80km/3600s
80 000m/3600s =>22,22m
☺