Answer:
The probability that the instrument does not fail in an 8-hour shift is 
The probability of at least 1 failure in a 24-hour day is 
Step-by-step explanation:
The probability distribution of a Poisson random variable X representing the number of successes occurring in a given time interval or a specified region of space is given by the formula:

Let X be the number of failures of a testing instrument.
We know that the mean
failures per hour.
(a) To find the probability that the instrument does not fail in an 8-hour shift, you need to:
For an 8-hour shift, the mean is 

(b) To find the probability of at least 1 failure in a 24-hour day, you need to:
For a 24-hour day, the mean is 

Answer:
Data: for the 10 days of practice, we have:
0.5 hours 1 time.
0.75 hours 2 times
1 hour 3 times
1.25 hours 2 times
1.5 hours 1 time
2 hours 1 time.
A) the largest amount number of times that she practiced by the same amount of time is 3 (for the 1-hour practice)
The smallest is 1 ( for the 0.5h, 1.5h, and 2h practices)
the difference is 3 - 1 = 2.
B) the time that she practiced more times is 1 hour, she practiced that amount of time in 3 different days out of the 10 days.
C) the equation can be found by multiplying the number of hours by the number of times that she practiced that amount of time, and then adding all of them:
0.5h*1 + 0.75h*2 + 1h*3 + 1.25h*2 + 1.5h*1 + 2h*1
D) the solution for the previous equation is 11 hours. Here the correct option is A.
For the answer to the question above,
and we are told that there are "four times as many quarters as nickels"
this translates to
q = 4n
0.05n + 0.25q = 2.10
and
q = 4n
are your two equations that could be used to solve this problem
if you would like to know how many nickels and how many quarters there are, plug in q = 4n into the first equation and get
0.05n + 0.25(4n) = 2.10
then I would stop here
because I didn't see the choices. So the answer is 4n
To solve this you would have to subtract 75 minutes from 5:00.
This would make the start time 3:45 pm.