A coin is tossed twice, what is the probability that atleast one tail occurs?
Here S={HH,HT,TH,TT}
∴ Number of possible outcomes n (S) =4
Let E be the event of getting at least one tail
∴ n (E) = 3
∴ Probability of getting at least one tail
P(E)=n(E)n(S)=34