re bonjour voici le 2ème ! encore merci infiniment !​

Bonsoir,

a. 1/3 h = 1/3 x 60 = 60/3 = 20 min

1/2 h = 1/2 x 60 = 60/2 = 30 min

--> 50 min

b. 1/6 h = 1/6 x 60= 60/6 = 10 min

5/12 h = 5/12 x 60 = 300/12 = 25 min

--> 35 min

c. 7/20 h = 7/20 x 60 = 420/60 = 21 min

2/3 h = 2/3 x 60 = 120/3 = 40 min

--> 61 min.