mmb1

Verified answer

1/n(n+1) = (n+ 1 - n)/n(n+1) = 1/n - 1/(n+1)

1/1*2 = 1/1 - 1/2

1/2*3 = 1/2 - 1/3

1/999*1000 = 1/999 - 1/1000

1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + ..... + 1/998 - 1/999 + 1/999 - 1/1000 = 1 - 1/1000 = 999/1000 = 0.999

ответ Е