Answer:
The probability is 
Step-by-step explanation:
If she has n distinct password candidates and only one of which will successfully log her into a secure system, the probability that her first first successful login will be on her k-th try is:
If k=1

Because, in her first try she has n possibles options and just one give her a successful login.
If k=2

Because, in her first try she has n possibles options and n-1 that are not correct, then, she has n-1 possibles options and 1 of that give her a successful login.
If k=3

Because, in her first try she has n possibles options and n-1 that are not correct, then, she has n-1 possibles options and n-2 that are not correct and after that, she has n-2 possibles options and 1 give her a successful login.
Finally, no matter what is the value of k, the probability that her first successful login will be (exactly) on her k-th try is 1/n
It’s really easy all you have to do is plug in the numbers
(In order)
-1, 1, 3, 5, 7, 9
The answer is in the image. We need 3.625 gallons to fill the tank.
Answer:
38.72%
Step-by-step explanation:
Estimated attendance = 1,000
The actual value of attendance = 1,632
We need to find the percent error of Shaun's estimate. Using the formula as follows :

Put all the values,

So, the percent error of Shaun's estimate is 38.72%.