你好!
1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256
=(1-1/2)+(1/2-1/4)+...+(1/128-1/256)
=1-1/2+1/2-1/4+1/4...-1/256
=1-1/256
=255/256
【希望可以帮到你】