Bonjour,
1)
a: 1/2 + 1/2 +1/2 =3/2
b: 50/60 = 5/6
2)
a: 3/4 + 3/2 + 5/6
= 9/12 + 18/12 + 10/12
= 37/12
b:
12/12 + 12/12 +12/12 +1/12
= 1+1+1+1/12
= 3 h +60/12
= 3h5mn
