bjr
1 1 1 1
A = 1 - ---------------- = 1 - ------------- = 1 - ------------- = 1 - ----- = 1 + 1 = 2
1 1
1 - ---------- 1 - ----- 1 - 2 -1
1 - 1/2 1/2
1 1 1 1
B = 1 - ------------------ = 1 - ---------------- = 1 - --------- = 1 - ------ = 1 + 2 = 3
1 1
1 - ----------- 1 - ------ 1 - 3/2 -1/2
1 - 1/3 2/3
1 1 1 1
C = 1 - --------------- = 1 - ----------------- = 1 - -------------- = 1 - --------------- =
1 1 n n - 1 - n
1 - ---------- 1 - ----------- 1 - ------- ------------
1 - 1/n (n-1)/n n - 1 n - 1
1
= 1 - --------------- = 1 + n - 1 = n
-1
--------
n - 1
