Răspuns :
3 + 6 + 9 + 12 + 15 + 18 = 63 prob3eme
77 - 63 = 14
14 + 7 = 2 probleme in prima zi
2 + 3 = 5 a 2-a zi
5 + 3 = 8 a 3-a zi
8 + 3 = 11 a 4-a zi
11 + 3 = 14 a 5-a zi
14 + 3 = 17 a 6-a zi
17 + 3 = 20 a 7-a zi
2 + 5 + 8 + 11 + 14 + 17 + 20 = 77 probleme
77 - 63 = 14
14 + 7 = 2 probleme in prima zi
2 + 3 = 5 a 2-a zi
5 + 3 = 8 a 3-a zi
8 + 3 = 11 a 4-a zi
11 + 3 = 14 a 5-a zi
14 + 3 = 17 a 6-a zi
17 + 3 = 20 a 7-a zi
2 + 5 + 8 + 11 + 14 + 17 + 20 = 77 probleme
a+a+3+a+6+a+9+a+12+a+15+a+18=77
7a+63=77
7a=77-63
a=14:7
a=2 prob. pe zi a rezolvat
2+5+8+11+14+17+20=77
7a+63=77
7a=77-63
a=14:7
a=2 prob. pe zi a rezolvat
2+5+8+11+14+17+20=77