[" 45) "1+3+7+15+31+..." to "n" terms "],[[" (1) "2x+1," ? "16],[" (1) "2+1,-n],[" (3) "2^(n)-1," 8"]]

1/2+3/4+7/8+15/16+..... t o n terms =

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

The sum of the series 2/3+8/9+(26)/(27)+(80)/(81)+ to n terms is (a) n-1/2(3^(-n)-1) (b) n-1/2(1-3^(-n)) (c) n+1/2(3^n-1) (d) n-1/2(3^n-1)

Sum of n terms of the series 1,3,7,15,31,dots... is

Sum to n terms the series 1+3+7+15+31+...