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

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

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

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

Sum of the first n terms of the series 1/2+3/4+7/8+(15)/(16)+......... is equals to (a). 2^n+n-1 (b). n-1+2^(-n) (c). 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 equals to (a). 2^n-n-1 (b). 1-2^(-n) (c). 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 equals to (a). 2^n-n-1 (b). 1-2^(-n) (c). 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 equals to (a). 2^n-n-1 (b). 1-2^(-n) (c). n+2^(-n)-1 (d).None of these