1:7=0 rest 1
2:7=0 rest 2
3:7=0 rest 4
4:7=0 rest 5
5:7=0 rest 7
6:7=0 rest 8
7:7=1
8:7=1 rest 1
9:7=1 rest 2
10:7=1 rest 4
11:7=1 rest 5
12:7=1 rest 7
13:7=1 rest 8
14:7=2
15:7=2 rest 1
16:7=2 rest 2
17:7=2 rest 4
18:7=2 rest 5
19:7=2 rest 7
20:7=2 rest 8
3x(1+2+4+5+7+8) =3x 27 = 81
Sper ca te-am ajutat! Acum e corect???