Question

What is the probability of getting $2$ heads in $2$ tosses?

Answer 1

Find the probability of getting $2$ heads in $2$ tosses

The probability of an event is,

$\mathbf{\text{P}}\left(E\right)\mathbf{}\mathbf{=}\mathbf{}\frac{\mathbf{Number}\mathbf{}\mathbf{of}\mathbf{}\mathbf{favourable}\mathbf{}\mathbf{outcomes}}{\mathbf{Total}\mathbf{}\mathbf{number}\mathbf{}\mathbf{of}\mathbf{}\mathbf{outcomes}}$

When a coin is tossed $2$ times, the possible outcomes are:

$HT,HH,TH,TT$

The total number of outcomes $=4$

Let $E$ be the event of getting $2$ heads.

$E=\left\{HH\right\}$

The number of favourable outcome $=1$

Then, the probability of getting $2$ heads is,

$P\left(E\right)=\frac{1}{4}$

Hence, the probability of getting $2$ heads in $2$ tosses is $\frac{1}{4}$.