Expression = $$1+frac{1}{2}+frac{1}{4}+frac{1}{16}+frac{1}{32}+frac{1}{64}$$ = $$(1+frac{1}{2}+frac{1}{2^2}+frac{1}{2^3}+frac{1}{2^4}+frac{1}{2^5}+frac{1}{2^6})-(frac{1}{8})$$ The first term above is a geometric progression with first term, $$a=1$$ and common ratio, $$r=frac{1}{2}$$ Number of terms, $$n=7$$ Sum of $$n$$ terms of G.P. (when $$r Ans - (B)