Răspuns:
Explicație pas cu pas:
n : 27 = cat rest < 27; restul = 2 x cat < 27 => 0 < cat < 14
n = 27 x cat + restul
n = 27 x cat + 2 x cat
n = 29 x cat
n = 29 x 1; = 29 x 2; 29 x 3; = 29 x 4; .........= 29 x 13
n = M₂₉ ≤ 29 x 13
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S = 29 + 58 + 87 + 116 + .......+ 348 + 377
→ 13 termeni are suma
S = 13 × ( 29 + 377 ) : 2
S = 13 × 406 : 2
S = 13 × 203
S = 2639