Question

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

Answer 1

Let $S$ be sample space of experiment and $A$ be event that at the most one tail turns up.
Then,
$S=\{HH,HT,TH,TT\}$
$A=\{HH,HT,TH\}$
$\text{Total number of cases}=4$
$\text{Total number of favorable cases}=3$
$\therefore \text{Required probability}=\frac{\text{No. of favorable cases}}{\text{Total no. of cases}}=\frac{3}{4}$