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%
The side of the square is (12x+52)/4=3x+13.
1/2=3/6
3/6+1/6=4/6 goodluck
Answer:
Assuming "the speaker takes up 1/6 of the internal volume"
volume is 9³ in³
you want the remaining volume, which is 5/6 of the total
(5/6)9³ = 607.5 in³
double that if you want the remaining volume for BOTH speakers....
I believe the answer is A because you cannot find x nor y