In a game, a person is paid Rs. 2 if he gets all heads or all tails when three coins are tossed, and he will pay Rs. 2 if either one or two heads show. What can he expect to win on an average per game? |
Lose Rs. 1 per toss of the coins. Win Rs. 1 per toss of the coins. Lose Rs. 2 per toss of the coins. No profit, no loss. |
Lose Rs. 1 per toss of the coins. |
The correct answer is Option (1) → Lose Rs. 1 per toss of the coins. $\text{Total outcomes when 3 coins are tossed}=8$ $\text{All heads or all tails: } \{HHH,TTT\}\Rightarrow 2 \text{ outcomes}$ $\text{Exactly 1 or 2 heads: } 6 \text{ outcomes}$ $\text{Payoff:}$ $+2 \text{ for } 2 \text{ outcomes},\quad -2 \text{ for } 6 \text{ outcomes}$ $\text{Expected value }E=\frac{2(+2)+6(-2)}{8}$ $= \frac{4-12}{8}$ $= \frac{-8}{8}$ $= -1$ The person can expect to lose Rs. 1 per game. |