Question

Question 38(ii)
In a game, the entry fee is of Rs 5. The game consists of a tossing a coin 3 times. If one or two heads show, Sweta gets her entry fee back. If she throws 3 heads, she receives double the entry fees. Otherwise, she will lose. For tossing a coin three times, find the probability that she
gets double entry fee.

Answer 1

Total possible outcomes of tossing a coin 3 times,
S = {(HHH), (TTT), (HTT), (THT), (TTH), (THH), (HTH), (HHT)}
$\therefore n\left(S\right)=8$
Let $E_2$ = Event that Sweta gets double entry fee
= She tosses heads on three times ={(HHH)}
$n\left(E_2\right)=1$
$\therefore P\left(E_2\right)=\frac{n\left(E_2\right)}{n\left(S\right)}=\frac{1}{8}$