$A$ missing helicopter is reported to have crashed somewhere in the rectangular region shown in the figure. What is the probability that it crashed inside the lake shown in the figure?

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

Two dice,one blue and one grey,are thrown at the same time. Write down all the possible outcomes. What is the probability that the sum of the two numbers appearing on the top of the dice is
$(i)$ $8 ?$
$(ii)$ $13 ?$
$(iii)$ less than or equal to $12 ?$

$A$ 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.

$A$ 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) $D$?

$A$ die is thrown once. Find the probability of getting:
$(i)$ a prime number;
$(ii)$ a number lying between $2$ and $6$;
$(iii)$ an odd number.