Răspuns :
Răspuns:
Explicație pas cu pas:
numerele sunt 13, 14, 15, 16,......., 37
13 : 13 = 1 rest 0
14 : 13 = 1 rest 1
15 : 13 = 1 rest 2
.
25 : 13 = 1 rest 12
26 : 13 = 2 rest 0
27 : 13 = 2 rest 1
.
37 : 13 = 2 rest 11
0 + 1 + 2 + .... + 12 + 0 + 1 + .... + 11 = 144
Cele 25 de numere consecutive sunt:
13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37.
Suma resturilor împărțirii la 13 a numerelor de mai sus este:
0+1+2+3+4+5+6+7+8+9+10+11+12+0+1+2+3+4+5+6+7+8+9+10+11=
=(1+2+3+4+5+6+7+8+9+10+11) + 12 + ( 1+2+3+4+5+6+7+8+9+10+11)=
=12+2·(11·12)/2 =12+132= 144.