6. Suppose that a password for a computer system must have at least 6, but no more than 9 characters, where each character in the password is a lowercase English letter, or an uppercase English letter, or a digit, or one of the five special characters *, <, >,!, and #.
(a) How many different passwords are available for this computer system?
(b) How many of these passwords contain at least one occurrence of at least one of the five special characters?
(c) Using your answer to part (b), determine how long it takes a hacker to try ev ery possible password, assuming that it takes one microsecond for a hacker to check each possible password.
Answers
a. There are 26 letters in the English alphabet, with two cases for each letter; 10 numerical characters in the range 0-9; and 5 special characters; thus a total of 26•2 + 10 + 5 = 67 characters.
Any character can be used more than once, so there are
67⁶ + 67⁷ + 67⁸ + 67⁹
or 27,618,753,243,839,080 total possible passwords.
b. If we require at least 1 special character, then there are 62 choices for each ordinary character we use and 5 for each special character.
Suppose we use a password of length 6. Then there are
62⁵•5¹ + 62⁴•5² + 62³•5³ + 62²•5⁴ + 62¹•5⁵ + 62⁰•5⁶
or
[tex]\displaystyle \sum_{k=1}^6 62^{6-k}\cdot5^k[/tex]
We count the longer passwords in a similar fashion:
[tex]\displaystyle \sum_{m=6}^9 \left(\sum_{k=1}^m 62^{m-k}\cdot5^k\right)[/tex]
or 1,206,930,268,794,100 total passwords
c. 1 second (s) is equal to 10⁶ microseconds (μs). If it takes 1 μs to try 1 password, then it would take
(1,206,930,268,794,100 passwords) • (1 μs / password) • (1 s / 10⁶ μs)
= 1,206,930,268.7941 s
= (1,206,930,268.7941 s) • (1 min / 60 s)
≈ 20,115,504.4799 min
≈ (20,115,504.4799 min) • (1 h / 60 min)
≈ 335,258.408 h
≈ (335,258.408 h) • (1 day / 24 h)
≈ 13,969.1003 days
≈ (13,969.1003 days) • (1 year / 365 days)
≈ 38.2715 years
Related Questions
Look at picture for question.
Answers
Answer:
A) - 3/7
B) -1/5
C) - 0.4
Step-by-step explanation:
HOPE IT CAN HELP YOU LOVELOTS
what is 0.5734 rounded to the nearest thousandth
Answers
Answer:
0.573
Hope that helps :)
Explanation:
3 is the thousandths, so you would round up by looking at the number to the right which is 4. Since 4 is not greater than 5, it wouldn’t change the 3.
Timmy has a total of 15 dimes and nickles i his pocket. He has 7 more dimes than nickels. How many dimes does he have.
Answers
Answer:
1.98 I think sorry if it's wrong
Louis is comparing the populations of several nearby cities. The population of Liberty Crossing can be written as 49 people, and the population of Harrisburg can be written as 47 people. The population of Glenview is 43 times the population of Harrisburg. Drag the cities to put them in order from least population (top) to greatest population (bottom).
Answers
Step-by-step explanation:
Louis is comparing the populations of several nearby cities. The population of Liberty Crossing can be written as 49 people, and the population of Harrisburg can be written as 47 people. The population of Glenview is 43 times the population of Harrisburg. Drag the cities to put them in order from least population (top) to greatest population (bottom).
The order of the cities from least population to greatest population:
Harrisburg
Glenview
Liberty Crossing
Given the information provided:
Harrisburg: This city has a population of 47 people. It's the smallest population among the three cities.
Glenview: The population of Glenview is 43 times the population of Harrisburg.
Since Harrisburg has 47 people, the population of Glenview would be 43 x 47 = 2021 people.
So, Glenview has a larger population than Harrisburg but is still smaller than Liberty Crossing.
Liberty Crossing: The population of Liberty Crossing is given as 49 people, which is the largest population among the three cities.
So, the correct order from least population to greatest population is:
Harrisburg
Glenview
Liberty Crossing
Learn more about Ascending order click;
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can you please help out my daughter on this...
Answers
Answer:
d
Step-by-step explanation:
Point J(-3, -7) was rotated to J'(7, -3). How
many degrees was the rotation?
Answers
Answer:
90 clockwise
Step-by-step explanation:
Answer:
270 degrees
Step-by-step explanation:
If both numbers are negative it means its in the lower left quadrant, so to reach 7 and -3, that means we need to reach the lower right quadrant so a 270 degree turn works
there are 350,000 in a warehouse predict the number of light bulbs that are likely to have no defects
Answers
Answer:
175000.(or around that number)
Step-by-step explanation:
half of 350,000 is 175000.
Help help help
Help hep help
Answers
Answer:
-2
Step-by-step explanation:
-4x-2x ≤ 17-5
-6x ≤ 12 | /(-6)
x ≥ -2
scientific form of 47500000000
Answers
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Scientific notation for above value is ~
[tex]4.75 \times 10 {}^{10} [/tex][tex]Hello[/tex] [tex]There![/tex]
First, let's make sure our coefficient is between 1 and 10:
4.75
All numbers in scientific notation look like this:
___x10^- (some number)
4.75x10^
Now, the number is large, so the exponent is positive.
So we move the decimal place some number of units. We move the decimal place 10 units, so the exponent is 10:
4.75x10^10
Hope this helps!
~Just a felicitous girlie
#CarryOnLearning
[tex]SilentNature[/tex]
A parabola having its axis vertical passes through three points A(0,0), B(1,0), and C(5,-20) respectively. Determine the coordinates of the vertex of the parabola.
Answers
Answer:
(1/2, 1/4)
Step-by-step explanation:
This is gonna be long. The x coordinate of a parabola's vertex = -b/2a. Now we have to find the equation of the parabola. Using the given points and plugging them into y=ax^2 + bx + c, we can determine:
0 = c
0 = a + b
-20 = 25a + 5b
After rearranging and solving, we get:
b = -a
-20 = 20a
a = -1
b = 1
y = -x^2 + x
Now we can find the x coordinate of the vertex, which is 1/2. After plugging this into our parabola, we get a y coordinate of -1/4 + 1/2 = 1/4. Therefore, the vertex is located at (1/2, 1/4).
Can anyone help me with this one asap? Thanks in advance.
Answers
The answer to your question is in the image above.
pls helpppppp i begggg
Answers
Answer
x Is less than 4
Step-by-step explanation:
It will be an open circle and the arrow is going the left direction on the number 4
There are 150 buttons in a box.
24 children take 3 buttons each.
How many buttons are left in the box?
Show your method.
Answers
The answer is 78 :)
Answer:
78 buttons left
Step-by-step explanation:
I multiplied 24 children by 3 buttons because each child took 3 buttons and I got 72 buttons taken.
Then I subtracted 150 buttons which is the starting number by 72 buttons (the amount taken by the child's) to get 78 buttons left in the box. ( I just separated negative 72 buttons into -50 and -22 to make it easier)
For a weekly car rental, a car rental company charges customers a flat fee of $100 plus
10 cents for every mile traveled.
15 Write an equation for the amount, A dollars, of a weekly rental for a car that travels
m miles
Answers
The way you typed out this sentence was a bit confusing but I think you were saying...
For a weekly car rental, a car rental company charges customers a flat fee of $100 + and charges 10 cents for every mile traveled. write an equation for the amount of a weekly rental car that travels 15 miles (Please let me know if I am wrong)
The equation would be
10+10 +10+ 10+ 10+ 10+ 10+ 10+ 10+ 10+ 10+ 10+ 10+ 10+ 10 = 150 cents
so they would be charging $1.50
Hoped this helped!
Have a great day/night! :)
A random number generator picks a number from 6 to 66 in a uniform manner. Round answers to 4 decimal places when possible.
The mean of this distribution is =
The standard deviation is =
The probability that the number will be exactly 19 is P(x = 19) =
The probability that the number will be between 28 and 46 is P(28 < x < 46) =
The probability that the number will be larger than 48 is P(x > 48) =
P(x > 17 | x < 62) =
Find the 49th percentile =
Find the maximum for the lower quartile =
Answers
Answer:last one
Step-by-step explanation:
A random number generator picks a number from 6 to 66 in a uniform manner, its resultants are mathematically given as
X=36[tex]\sigma=5[/tex]p(x=19)=0.2167P(28 < x < 46) =0.3 P(x > 48)=0.3P(x > 17 | x < 62) =0.75k=29.4h=15What is the mean of this distribution?Generally, the equation for Mean is mathematically given as
[tex]X=\frac{a+b}{2}\\\\Therefore\\\\X=\frac{6+66}{2}[/tex]
X=36
b)
Generally, the equation for standard deviation is mathematically given as
[tex]\sigma=\sqrt{\frac{b-a}{12}^2}\\\\Therefore\\\\\sigma=\sqrt{(\frac{66-6}{12})^2}\\\\\sigma=\sqrt{25}\\\\[/tex]
[tex]\sigma=5[/tex]
c)
The probability that the number will be exactly 19
[tex]p(x=19)=\frac{19-6}{66-6}[/tex]
p(x=19)=0.2167
d)
The probability that the number will be between 28 and 46 is P(28 < x < 46)
[tex]P(28 < x < 46) =\frac{46-6}{66-6} -(\frac{28-6}{66-6})[/tex]
P(28 < x < 46) =0.3
e)
The probability that the number will be larger than 48 is P(x > 48)
[tex]P(x > 48)=1-P(x\leq 48)[/tex]
Therefore
[tex]P(x > 48)=1-(\frac{48-6}{66-6})[/tex]
P(x > 48)=0.3
f)
[tex]P(x > 17 | x < 62) = P(x\leq 62-P(x leq 17))[/tex]
Therefore
[tex]P(x > 17 | x < 62) =\frac{62-6}{66-6}-(\frac{17-6}{66-6})[/tex]
P(x > 17 | x < 62) =0.75
g)
The 49th percentile
[tex]p(x\leqk=k.(1/66-6))[/tex]
Therefore
[tex]0.49=k*(1/(66-6))[/tex]
k=29.4
h)
The maximum for the lower quartile
P(xl)=h*1/60
0.25=h*1/60
h=15
Read more about probability
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At a local print shop, 14 copies can be made for $4. At this rate, how how many copies could be made for $8?
Full explanation (No links)
Answers
Answer:
28
Step-by-step explanation:
the ratio is written as copies/dollars.
14/4=x/8
since we can multiply 4 by 2 to get 8, multiply 14 by 2 as well.
14/4=28/8
The reason that’s correct is because $8 is 2 times more than $4. So we would do 14 (which is the amount of copies that are made for $4) x 2 = 28 copies
(x-4)2 = 36
Which of the following expressions represents the solutions to the given equation?
0-4+ V(36)
O4 + V(36)
16+ (36)
Answers
1. X-4= 6. That is equal to 10 so x1=10
2. X-4= -6. That is equal to -2 so x2= -2
rewrite 12/12 as a whole number
Answers
9514 1404 393
Answer:
1
Step-by-step explanation:
Any (non-zero) number divided by itself is 1.
_____
This is a fact that has many uses in problem solving and units conversion.
If $20,000 is invested at 7% for 15 years, find the future value if the interest is compounded daily(365 days)
Answers
Answer:
The total compound interest is $37,147.24.
Step-by-step explanation:
I could be wrong
what is 2x-4y=12 x-3y=17
Answers
Answer:
x=-16
y=-11
Explanation:
2x-4y=12
x-3y=17
first multiply all the numbers of the bottom equation by -2
2x-4y=12
-2x+6y=-34
then cancel the x's, and add the other numbers
2y=-22
solve for y
y=-11
plug y into either the original top or bottom equations
2x-4(-11)=12
2x+44=12
2x=-32
x=-16
or
x-3(-11)=17
x+33=17
x=-16
find the perimeter of the triangular shaped sandwich
Answers
Answer:
P = 12 + 5x
Step-by-step explanation:
P = a + b + c
P = 7 + (x + 4) + (4x + 1)
= 7 + x + 4 + 4x + 1
= 12 + 5x
Joe cuts ten pizzas into quarters. How many pizza quarters are there in total?
Answers
Answer:
40 pizzas in total
Step-by-step explanation:
10×4=40
Kathy is following a recipe for punch that calls for 3 liters
of juice. She has 3 quarts of juice. Without using an equation, does Kathy
have enough juice for the punch? Explain.
Answers
Answer:
Yes, Kathy does have enough juice.
Step-by-step explanation:
Kathy does have enough because quarts are a little bigger than liters, so the 3 quarts she has will cover the liters.
What is the image of the point (1,-4) after a rotation of 180° counterclockwise
about the origin?
Answers
Answer:
(-1, 4)
Step-by-step explanation:
Rotation 180° negates both coordinates:
(x, y) ⇒ (-x, -y)
The direction (clockwise or counterclockwise) is irrelevant. It is the same as reflection across the center of rotation (the origin).
(1, -4) ⇒ (-1, 4) . . . . after rotation 180°
HELLP ILL GIVE BRSINLY
Answers
m = 180 - CBE = 180 - [ 360 - BDC - BED - (180 - DCE - DEC)] = 180 - [ 360 - 90 -90 - (180 - 13*2)] = 154
P/s: 180 - DCE - DEC = CDE
ok done. Thank to me :>
if 1/2x + 6 = -x -3, what is the value of -2x?
Answers
Answer:
12
Step-by-step explanation:
Hi there!
We are given the following equation:
1/2x + 6 = -x-3
And we want to find the value of -2x
First, let's solve for x, and then substitute the number found as x into -2x to find the value of -2x
Start by adding x to both sides to remove -x from the right side
1/2x + 6 = -x -3
+x +x
_______________
3/2x+6=-3
Subtract 6 from both sides to remove it from the left side
3/2x=-9
Multiply both sides by 2/3 in order to clear the fraction
x=-6
Now substitute -6 as x into -2x
-2x
x=-6
-2(-6)=12
Hope this helps!
find the value of the angles marked 'x' and 'y'
Answers
Answer:
x=120 y=60
Step-by-step explanation:
Interior angle of a hexagon = 120
Straight line = 180
180-120=60
workout the size of angle x
Answers
Answer:
Where is it?
Step-by-step explanation:
Find the area of a rectangle with sides measurements 8 inches and 17 inches
Answers
Answer:
136 inches or 354.44cm
Step-by-step explanation:
17*8 = 136
Answer:
136 inches
Step-by-step explanation:
17 X 8 = 136 inches
A patio measures 4 yd long and 3 yd wide. What is the area in square meters? Round final answer to two decimal places
Answers
Answer:
Step-by-step explanation:
1 yd(36 in/yd)(2.54 cm/in) / (100cm/m) = 0.9144 m
(4(0.9144)) x (3(0.9144)) = 10.03352832 = 10.03 m²