Because the ninth floor is 1/2 on the first floor, x=2(x-9y) gives x= 16y.
Because the ninth floor is *** 108, so: x+(x-y)+(x-2y)+(x-3y)+...+(x-8y) =108, the solution is 9x-36y = 65438+.
9* 16y-36y= 108 gives y= 1, so x= 16, and each floor has 16, 15, 14 respectively.