A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box, find the probability that it bears
(i) a two-digit number
(ii) a perfect square number
(iii) a number divisible by 5.
(i) \( \dfrac{9}{10} \)
(ii) \( \dfrac{1}{10} \)
(iii) \( \dfrac{1}{5} \)