Question

If two coin are tossed, then find the probability of the event that no 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 no head.
$\therefore A=TT$
$\therefore n\left(A\right)=1$
$P\left(A\right)=\frac{n\left(A\right)}{n\left(S\right)}=\frac{1}{4}$