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

(N/A) In the experiment of tossing a coin once, the total number of possible outcomes is $2$ $-$ Head $(H)$ and Tail $(T).$
Let $E$ be the event of 'getting a head'. The number of outcomes favourable to $E$ is $1.$
Therefore, $P(E) = P(\text{head}) = \frac{\text{Number of outcomes favourable to } E}{\text{Total number of possible outcomes}} = \frac{1}{2}.$
Similarly, if $F$ is the event of 'getting a tail', the number of outcomes favourable to $F$ is $1.$
Therefore, $P(F) = P(\text{tail}) = \frac{1}{2}.$