161k views
1 vote
A fair coin is tossed twice in succession. The set of equally likely outcomes is {HH, HT, TH, TT}. What is the probability of getting exactly two tails?

User GutenYe
by
7.9k points

2 Answers

4 votes

Answer: 0.25

Explanation:

Given : A fair coin is tossed twice in succession.

The set of equally likely outcomes is {HH, HT, TH, TT}.

i.e. The total number of outcomes = 4

In order to get exactly two tails , the total number of favorable outcomes = 1 (TT)

We know that ,
\text{Probability }=\frac{\text{Favorable outcomes}}{\text{Total number of outcomes}}

Then, the probability of getting exactly two tails =
(1)/(4)=0.25

Hence, the required probability = 0.25

User RumTraubeNuss
by
8.2k points
6 votes
The probability is 1/4
This is because:
Probability of first tails = 1/2
Probability of second tails = 1/2
Probability of first AND second tails = 1/2 * 1/2
= 1/4
This is also visible in the set of outcomes
User Dmitry Leiko
by
7.9k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.