# For the experiment of tossing a coin three times, how do you find the probability of getting at least two heads?

Aug 22, 2017

$\frac{1}{2}$

#### Explanation:

Since we only have three throws it will be easier to list all possibilities, of 1st, 2nd and 3rd throws

$H =$ head

$T =$Tail

$\textcolor{b l u e}{H H H}$

$\textcolor{b l u e}{H H T}$
$\textcolor{b l u e}{H T H}$
$\textcolor{b l u e}{T H H}$

$T T H$
$T H T$
$H T T$

$T T T$

Eight possibilities in all, and the requirement of at least two heads is shown in blue

$X = \text{ number of heads}$

$P \left(X \ge 2\right) = \frac{4}{8} = \frac{1}{2}$

Aug 22, 2017

1/2

#### Explanation:

total possible case :- HHH, HHT, HTH, THH, TTT, TTH, THT, HTT

At least two heads :- 4

so the probability of getting at least two head is 4/8 = 1/2