The sum of the first n terms of the series `(1)/(2)+(3)/(4)+(7)/(8)+(15)/(16)+....` is equal to

If the sum of the first n terms of the series

Sum of the first n terms of the series (1)/(2)+(3)/(4)+(7)/(8)+(15)/(16)+... is equal to (1988,2M)2^(n)-n-1(b)1^(6)-2^(-n)n+2^(-n)-1(d)2^(n)+1

Sum of the first n terms of the series (1)/(2)+(3)/(4)+(7)/(8)+(15)/(16)+... is equal to 2^(n)-n-1 b.1-2^(-n) c.n+2^(-n)-1 d.2^(n)+1

The sum of the first 20 terms of the series 1+(3)/(2)+(7)/(4)+(15)/(8)+(31)/(16)+... is:

The sum to n terms of the series (1)/(2)+(3)/(4)+(7)/(8)+(15)/(16)+....isgivenby

The sum of first n terms of the series (2)/(3)+(8)/(9)+(26)/(27)+...... is