Which of the following cannot be the probability of an event?

$A$ bag contains $5$ red balls and some blue balls. If the probability of drawing a blue ball is double that of a red ball,determine the number of blue balls in the bag.

$12$ defective pens are accidentally mixed with $132$ good ones. It is not possible to just look at a pen and tell whether or not it is defective. One pen is taken out at random from this lot. Determine the probability that the pen taken out is a good one.

Find the probability of getting a head when a coin is tossed once. Also find the probability of getting a tail.

$A$ child has a die whose six faces show the letters as given below:
$A$,$B$,$C$,$D$,$E$,$A$
The die is thrown once. What is the probability of getting:
$(i)$ $A$?
(ii) $D$?

$A$ 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 $5$.