Question

A coin is tossed $3$times what is the probability of getting at least two tails

Answer 1

Sample space for tossing $3$coins: $HHH,HTH,THH,TTH,HHT,HTT,THT,TTT$

Total number of possible outcomes$=8$

Probability of getting at least two tails is:

$\text{P(A)=P(getting two tails)+P(getting 3 tails)}$

$$\begin{gathered} =\frac{3}{8}+\frac{1}{8} \\ =\frac{4}{8}=\frac{1}{2} \end{gathered}$$

Therefore, the probability of getting at least $2$tails if you flip a coin $3$times is $\frac{1}{2}$.