Answer:
Third option: 
Step-by-step explanation:
<h3>
The correct exercise is attached.</h3>
The equation given is:

The steps to find the value of "x" are shown below:
1. Add 2 to both sides of the equation:

2. Descompose 9 and 27 into their prime factors:

3. Substitute them into the equation:

4. Knowing that If
, then
, we get:

5. Apply Distributive property:

6. Add 2 to both sides:

7. Divide both sides of the equation by 2:

Well, it really depends but it could be 9 rolls of quarters, 5 rolls of quarters and 8 rolls of dimes, 4 rolls of quarters and 10 rolls of dimes, 3 rolls of quarters and 12 rolls of dimes, etc.
Answer:

And replacing we got:

The probability that a randomly selected barber needs at least 14 minutes to complete the haircut is 0.5714
Step-by-step explanation:
We define the random variable of interest as x " time it takes a barber to complete a haircuts" and we know that the distribution for X is given by:

And for this case we want to find the following probability:

We can find this probability using the complement rule and the cumulative distribution function given by:

Using this formula we got:

And replacing we got:

The probability that a randomly selected barber needs at least 14 minutes to complete the haircut is 0.5714