[" 2.For a positive integer "n," series "1+(1)/(2)+(1)/(3)+...+(1)/((2^(n)-1))" is "],[[" (a) "n," (d) "<3n]]

For a positive integer n, let a(n)=1+(1)/(2)+(1)/(3)+(1)/(4)+ . . .+(1)/(2^(n)-1) Then:

For a positive integer n , let a(n) = 1+ 1/2 + 1/3 +…+ 1/(2^(n)-1) : Then

For a positive integer n let a(n)=1+1/2+1/3+1/4+.......+1/((2^n)-1) then

For a positive integer n let a(n)=1+1/2+1/3+1/4+.....+1/((2^n)-1)dot Then

For a positive integer n let a(n)=1+1/2+1/3+1/4+….+1/ ((2^n)-1) Then

For a positive integer (n gt 1) , Let a (n) = 1+ (1)/(2) + (1)/(3) + (1)/(4) ….... + (1)/( (2^(n) )-1) Then

For a positive integer n, let a_(n) = 1+( 1)/( 2) +( 1)/( 3) + ( 1)/( 4) + "......." + ( 1)/(( 2^(n) - 1)) . Then :

The lest positive integer n such that 1- (2)/(3)- (2)/(3^(2))- ….- (2)/(3^(n-1)) lt (1)/(100) , is

The least positive integer n, for which ((1+i)^(n))/((1-i)^(n-2)) is positive is