Concept:Expected value is the weighted average of all possible outcomes:
E(X)=∑xiP(X=xi).
Explanation:When 3 coins are tossed, total outcomes are
23=8.
All heads or all tails means only HHH and TTT, i.e., 2 favourable outcomes.
P(all heads or all tails)=82=41One head or two heads covers the remaining 6 outcomes.
P(one head or two heads)=86=43Let
X be the amount received per game.
P(X=100)=41, since he wins ₹100 in this case.
P(X=−40)=43, since he pays ₹40 in this case.
Now, expected value is:
E(X)=100×41+(−40)×43E(X)=25−30=−5Thus, on average, he loses ₹5 per game.
Answer:₹5 loss (Option B).