Question

A coin is tossed twice. If the outcome is at most one tail, what is the probability that both head and tail have appeared?

Answer 1

We know that a coin has two sides

Sample space S = {H, T}

Total no. of outcomes = 2

It is given that a coin is tossed twice.

Consider P (A) as the probability of getting at most 1 tail

Sample space of A = {(H, H), (H, T), (T, H)}

Consider P (B) as the probability of getting a head

Sample space of B = {H}

P (B) = 1/2

So the probability of getting at most one tail and a head

(A ∩ B) = {(H, H)}

P (A ∩ B) = 1/3

Here the probability that both head and tail have appeared can be written as