Divide a unit segment into 3 congruent segments and remove the middle

segment. Do this process a second time on each of the remaining two segments. If this process is carried out a total of n times, what is the sum of the lengths of the remaining segments?

W) One-third to the nth power

X) One minus one-third to the nth power

Y) Two-thirds to the nth power

Z) One minus two-thirds to the nth power
Y) TWO-THIRDS TO THE nth POWER