Answer:
35/79
Step-by-step explanation:
Assuming you can't choose the same song a second time, the probability is 35/79.
If you can choose the same song, the probability is 36/80, which reduces to 9/20.
I believe the answer is B.
Answer:
It doesn't. x = 22 271 201
Step-by-step explanation:
You are going to need a calculator no matter how you do it.

(a) The direct method

(b) The indirect method

Answer:
all real nunbers
Step-by-step explanation:
when we exchange the place of x and y and solve for y we get the equation y=x^2 + 2
any number inserted in x will give a value y
The exponential distribution is:

where

The probability we want is how likely will a dvd player last more than 8 years, given it has already lasted 5 years
To find this, you use conditional probability.

where A is P(x>8) and B is P(x>5)
To find these probabilities, integrate over the distribution:

Sub into conditional probability formula:

Final Answer: Given a dvd player is more than 5 years old, the probability that it will last another 3 more years is about 54.9%