Concept: The question tests on the area of Counting
Solution:
Rearranging, we get
x−18=3√x
Squaring both sides, x2−36x+324=9x
Rearranging, x^2−45x+324=0
x^2−36x−9x+324=0
=>x^2−36x−9x+324=0
x(x - 36) - 9(x - 36) = 0
(x - 36) (x - 9) =0
The solutions are 36 and 9 and the factors are 1,2,3,4,6,9,12,18 and 36.
8 is not a factor of the solutions.
Option D