Question

If two coins are tossed, then find the probability of the event that at least one head turns up.

Answer 1

Let S be the sample
Two coins are tossed.
$\therefore S=\{HH,HT,TH,TT\}$
$\therefore n\left(S\right)=4$
Let A be the event of getting atleast one head.
$\therefore A=\{HT,TH,HH\}$
$\therefore n\left(A\right)=3$
$P\left(A\right)=\frac{n\left(A\right)}{n\left(S\right)}=\frac{3}{4}$