98,271 views
30 votes
30 votes
You flip a coin twice what is the probability of getting heads and then getting heads

User Starson Hochschild
by
2.5k points

1 Answer

12 votes
12 votes

The probability that a single event A occurs is:


P=\frac{\text{ number of favorable outcomes of A}}{\text{ total number of outcomes}}

The probability of two consecutive events A and B is:


P=P(A)*P(B)

Let's calculate the probability of event A: getting heads.

Favorable outcome: heads.

Number of favorable outcomes: 1.

Total outcomes: heads, tails.

Number of total outcomes: 2.

So:


P(A)=(1)/(2)

Let's calculate the probability of event B: getting heads in the second flip.

Favorable outcome: heads.

Number of favorable outcomes: 1.

Total outcomes: heads, tails.

Number of total outcomes: 2.

So:


P(B)=(1)/(2)

Finally, let's find the probability of getting heads twice.


\begin{gathered} P=P(A)*P(B) \\ P=(1)/(2)*(1)/(2)=(1)/(4) \end{gathered}

Finding the probability in percentual:


\begin{gathered} P=(1)/(4)*100 \\ P=25\% \end{gathered}

Answer: 1/4 = 25%.

User Geert Smelt
by
2.6k points