$A$ 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?

Harpreet tosses two different coins simultaneously (say,one is of $Rs. 1$ and other of $Rs. 2$). What is the probability that she gets at least one head?

$A$ bag contains a red ball,a blue ball and a yellow ball,all the balls being of the same size. Kritika takes out a ball from the bag without looking into it. What is the probability that she takes out the
$(i)$ yellow ball?
$(ii)$ red ball?
$(iii)$ blue ball?

Two dice,one blue and one grey,are thrown at the same time.
$(i)$ Complete the following table:
$\begin{array}{|l|c|c|c|c|c|c|c|c|c|c|c|} \hline \text{Sum} & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 \\ \hline \text{Prob.} & \frac{1}{36} & & & & & & \frac{5}{36} & & & & \frac{1}{36} \\ \hline \end{array}$
$(ii)$ $A$ student argues that 'there are $11$ possible outcomes $2, 3, 4, 5, 6, 7, 8, 9, 10, 11$ and $12$. Therefore,each of them has a probability $\frac{1}{11}$.' Do you agree with this argument? Justify your answer.

$(i)$ $A$ lot of $20$ bulbs contains $4$ defective ones. One bulb is drawn at random from the lot. What is the probability that this bulb is defective?
$(ii)$ Suppose the bulb drawn in $(i)$ is not defective and is not replaced. Now one bulb is drawn at random from the rest. What is the probability that this bulb is not defective?

$A$ bag contains $3$ red balls and $5$ black balls. $A$ ball is drawn at random from the bag. What is the probability that the ball drawn is
$(i)$ red?
$(ii)$ not red?