1/2+1/4+1/8+1/16+1/2=(1-1/2)+(1/2-1/4)+(1/4-1/8)+(1/8-1/16)+1/2=1-1/2+1/2-1/4+1/4-1/8+1/8-1/16+1/2=1-1/16+1/2=15/16+1/2=23/16
