Bonjour,

fondant:

300/200 = 3/2

600/400 = 6/4 =3/2

150/100 = 3/2

80O/500 = 8/5

donc on le supprime

Vélo:

1h = 4*15mn

1) 20km/h

20/4 =  5km/h

2)  5km/h

3) 50/ 10

5km/h

4) 70/13

=>5,38km/h

Non proportionnel, on le supprime