Three coins are tossed simultaneously. What is the probability of getting at least two tails out of three?
1). 1/2
2). 1/3
3). 2/3
4). 1/4
⇒ Here, S = {(HHH), (HHT), (HTH), (HTT), (THH), (THT), (TTH), (TTT)}
⇒ n(S) = 23 = 8
⇒ Let event E = getting at least two tails
⇒ {(HTT), (THT), (TTH), (TTT)}}
∴ n(E) = 4
Now, probability of getting at least two tails
⇒ P(E) = n(E)/n(S) = 4/8 = 1/2