bonjour aider moi svp

Bonjour, 

Ex1

4m = 67,50€ ⇒ 1m = 16,875€ ⇒ 7m = 118,125€ ≈ 118,13€

Ex2
a) 
1h15min = 1h+15 min = 1h + 0,25h = 1,25h
vitesse = distance / temps = 105/1,25 = 84 km/h

b)
temps = distance / vitesse = 189/84 = 2,25h = 2h 15 min