Question

Brian flips a fair coin 3 times. What is the probability of getting exactly 2 tails?

Answer 1

Answer:

3/8

Step-by-step explanation:

The possible outcomes

TTT TTH THT THH  HHH HHT HTH HTT  = 8 outcomes

There are TTH THT HTT  3 with exactly two tails

P ( exactly 2 tails) = 3/8

Answer 2

Answer:

$\frac{3}{8}$

Step-by-step explanation:

The outcomes you are looking for are either HTT, THT, or TTH.

The possibility to toss tails or heads is 0.5. Thus the possibility to throw T and then H and then H is:

$\frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} = \frac{1}{8}$

We have three ways of getting 2 tails, the possibility of throwing exactly two tails in three tosses is:

$\frac{1}{8} + \frac{1}{8} + \frac{1}{8} = \frac{3}{8}$

0.375 is the probability of getting exactly 2 tails in 3 tosses.

{0 tails}={HHH}

{1 tails}={TTH, THT, HTT}

{2 tails}={HTT, TTH, THT}

{3 tails}={TTT}

There are 3 cases with getting two tails out of 8 possible outcomes.