Răspuns:
Explicație pas cu pas:
S = (1/2 + 1/3 + 1/4 + 1/5 + 1/6) + (1/2 + 2/3 + 3/4 + 4/5 + 5/6)
= (1/2 + 1/2) + (1/3 + 2/3) + (1/4 + 3/4) + (1/5 + 4/5) + (1/6 + 5/6)
= 2/2 + 3/3 + 4/4 + 5/5 + 6/6
= 1 + 1 + 1 + 1 + 1
= 5
