Răspuns :
a _______/
m _______/_______/_______/_______/
3 seg =21
21:3=7 fiecare seg egal
a=7
m=7x3=
/----/----/----/----/+9+21
/----/ Alina
4+1=5
9+21=30 Maria
30:5=6Alina
/----/ Alina
4+1=5
9+21=30 Maria
30:5=6Alina