If $P(A)$ denotes the probability of an event $A$,then

$A$ bag contains $10$ red,$5$ blue and $7$ green balls. $A$ ball is drawn at random. Find the probability of this ball being a
$(i)$ red ball
$(ii)$ green ball
$(iii)$ not a blue ball

Two unbiased dice are thrown once. Write all the possible outcomes of this experiment. What is the probability that the sum of numbers on two dice is greater than $9$?

Someone is asked to take a number from $1$ to $100$. The probability that it is a prime number is

If an event cannot occur,then its probability is

Two dice are thrown at the same time. Find the probability of getting:
$(i)$ same number on both dice.
$(ii)$ different numbers on both dice.