Two coins are tossed simultaneously. What is the probability of getting at least one tail?
Answer:
^@\dfrac { 3 } { 4 } ^@
- When two coins are tossed simultaneously, all possible outcomes are ^@ HH, HT, TH, TT^@.
The total number of all possible outcomes = ^@4^@.
- Let ^@E^@ be the event of getting at least one tail.
Therefore, ^@E^@ is the event of getting ^@1^@ tail or ^@2^@ tails.
So, the favourable outcomes from ^@ HH, HT, TH, TT^@ are ^@HT, TH^@ and ^@TT^@.
Number of favourable outcomes = 3. @^ \begin{aligned} \therefore \space P(\text{getting at least one tail}) = P(E) = \dfrac { 3 } { 4 }. \end{aligned} @^ - Therefore, the probabilty of getting at least one tail is ^@\dfrac { 3 } { 4 } ^@.