Layla guesses on all 20 questions of a multiple-choice test. Each question has 4 answer choices. What is the probability of a success and a failure for this experiment?

Answers

Answer 1

Step-by-step explanation:

what is the criteria for success ? how many questions must be right ? and how many must be wrong for failure ?

if success means all answers right, then she has 4 choices on the first question to pick one right answer. and then for each of those again 4 choices on the second question and so on.

so, all possible outcomes are 4²⁰.

that means the probability to guess all 20 right is

1/4²⁰

a tiny, tiny number.

and the probabilty to have all wrong ?

she has 4 choices to pick 1 of 3 wrong answers.

so, the probability is 3/4 to answer the first question wrong.

for that she has again then the same chance to get the second question wrong too.

so, it is 3/4 × 3/4 = 9/16

and so on.

the probability to guess all 20 wrong is then

(3/4)²⁰ ≈ 0.0032

that is still a small number but much, much larger than the probability to get everything right.

still, even the goal to truly get everything wrong is highly unlikely.


Related Questions

find the missing side length in the image below

Answers

Let missing side be x

Using basic proportionality theorem

[tex]\\ \sf\longmapsto \dfrac{45}{35}=\dfrac{x}{56}[/tex]

[tex]\\ \sf\longmapsto \dfrac{9}{7}=\dfrac{x}{56}[/tex]

[tex]\\ \sf\longmapsto 7x=9(56)[/tex]

[tex]\\ \sf\longmapsto x=\dfrac{9(56)}{7}[/tex]

[tex]\\ \sf\longmapsto x=72[/tex]




In the equation y = 39x + 50represents the number of people at a holiday dinner and y represents the total cost of
the dinner. If a family spent $518, how many people attended the dinner?

Answers

Answer:

The correct answer is - 12.

Step-by-step explanation:

Given:

Total number of people = y = 39x+50

Total amount spent y = 518

Solution:

The equation for the number of people who attended the dinner

y = 39x+50

The cost of dinner is equally divided by number of people =

then, 518 = y

placing value, 518 = 39x+50

x = (518-50)/39

= 468/39

= 12

Then number of people attended the dinner = 12

If one root of the quadratic equation is 2x2 +kx -6= 0 is 2
find the value of k

Answers

This is ur answer plz mark brainliest

A restaurant sold 250 drinks in a night. Some of the drinks were sold for $2 each, and the rest for $5 each. If the total sales of drinks for the night was $830, how many $2 drinks were sold?

110
140
145
150
155

?

Answers

Answer:

140

Step-by-step explanation:

Suppose,

x drinks were sold for 2$

y drinks were sold for 5$

therefore, x+y = 250....( 1 )

and 2x+5y = 830......( 2 )

multiply equation ( 1 ) with 2,

2x+2y = 500......( 3 )

Subtract equation ( 3) from (2)

3y = 330

or, y = 110

so, x = 140

so, 140 drinks were sold for 2$

140 drinks were sold for $2.

What are variables and how to define them?

A variable is any letter or symbol that represents a number with an unknown value.

We can define them simply by any alphabet like x or y.

What are linear equations and how to make them?

A linear equation is generally of the form Ax + By = C, where the two variables are x and y, while A, B and C are constants.

A constant is a value or number that never changes and it's constantly the same.

We have to choose our variables and put them in the equation such that it holds properly and satisfies all the conditions for the given question.

How to solve linear equations?

There are several methods of solving linear equations. we may have the linear equation with two or three or many variables. The methods are:

substitution method,elimination method,graphing method.

In the given question first, let's make our variables.

Let, the number of drinks was sold for 2$ is x, and the number of drinks was sold for 5$ is y.

And now we will try to make the linear equation with two variables because we have two variables satisfying the conditions in the question given.

One thing to remember carefully is that we have to have two equations if we have two variables.

The restaurant sold a total of 250 drinks so we can write,

x + y = 250  

The total sales of drinks for the night was $830 so again we can write,

2x + 5y = 830

Now, we have made the two equations, so we will solve them with help of the substitution method.

Let's, take the equation and just find the value of x,

x + y = 250

x = 250 - y

Now, we will substitute the value of x in the other equation,

2×(250 - y) +5y = 830

Multiplying 2 with the term (250 - y),

500 - 2y + 5y = 830

Now, solve for y,

500 +3y = 830

subtracting 500 both sides we get,

500 - 500 + 3y = 830 - 500

3y = 330

Dividing both sides by 3 we get,

(3y) / 3 = 330 / 3

y = 110

Now, again putting the value of y in the equation x + y = 250 we get,

x + 110 = 250

Subtracting 110 both sides we get,

x + 110 - 110 = 250- 110

x = 140

Now, we can conclude that the number of drinks sold for 2$ is 140 and the number of drinks sold for 5$ is 110.

Therefore, 140 drinks were sold for $2.

To know more about linear equations, making them and solving them click here - brainly.com/question/384631

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Need help really bad
Do,1 of X is
(4,0)
(4,1)
(5,1)

Answers

Answer:

(4,0)

Step-by-step explanation:

the dot is on 4 and the line is 0 so answer is 4,0

the answer to this question is (4,0)

Not sure whether the answer is 9 or -11, so please help

Answers

the answer is 9 , let me know if this is right !

factor 9-x^2 completely

Answers

Answer:

-(x + 3)(x - 3)

Step-by-step explanation:

Using the difference of squares we can factor this expression.

[tex](9 - x^2)\\= (3^2 - x^2)\\= (3 + x)(3 - x)\\= -(3 + x)(-3 + x)\\= -(x + 3)(x - 3)[/tex]

find csc theta and sin theta if tan theta = 7/4 and sin theta less than 0

Answers

9514 1404 393

Answer:

  sin(θ) = (-7√65)/65

  csc(θ) = (-√65)/7

Step-by-step explanation:

The angle will have the given characteristics if its terminal ray passes through the 3rd-quadrant point (-4, -7). The distance from the origin to that point is ...

  d = √((-4)² +(-7)²) = √65

The sine of the angle is the ratio of the y-coordinate to this value:

  sin(θ) = -7/√65

  sin(θ) = (-7√65)/65

The cosecant is the inverse of the sine

  csc(θ) = (-√65)/7

Which statement describes the end behavior of this function? g(x) = 1/2|x - 3| - 7
A. As x approaches positive infinity, g(x) approaches negative infinity.
B. As x approaches negative infinity, g(x) approaches negative infinity.
C. As x approaches positive infinity, g(x) approaches positive infinity.
D. As x approaches negative infinity, g(x) is no longer continuous.

Answers

Answer:

C. As x approaches positive infinity, g(x) approaches positive infinity.

Step-by-step explanation:

We are given the following function:

[tex]g(x) = \frac{|x-3|}{2} - 7[/tex]

End behavior:

Limit of g(x) as x goes to negative and positive infinity.

Negative infinity:

[tex]\lim_{x \rightarrow -\infty} g(x) = \lim_{x \rightarrow -\infty} \frac{|x-3|}{2} - 7 = \frac{|-\infty-3|}{2} - 7 = |-\infty| = \infty[/tex]

Positive infinity:

[tex]\lim_{x \rightarrow \infty} g(x) = \lim_{x \rightarrow \infty} \frac{|x-3|}{2} - 7 = \frac{|\infty-3|}{2} - 7 = |\infty| = \infty[/tex]

So in both cases, it approaches positive infinity, and so the correct option is c.

Find the missing side length, and enter your answer in the box below. If
necessary, round your answer to 2 decimal places.
6
8

Answers

a^2+b^2=c^2
6^2+8^2=c^2
36+64=c^2
100=c^2
square root 100 = square root c^2
10=c
answer is 10

The missing side length is 10 unit.

What is Pythagoras theorem?

The relationship between the three sides of a right-angled triangle is explained by the Pythagoras theorem, commonly known as the Pythagorean theorem. The Pythagorean theorem states that the square of a triangle's hypotenuse is equal to the sum of its other two sides' squares.

We have,

Perpendicular = 6

Base = 8

Using Pythagoras theorem

c² = P² + B²

c² = 6² + 8²

c²= 36 + 64

c² = 100

c= 10 unit.

Thus, the missing length is 10 unit.

Learn more about Pythagoras theorem here:

https://brainly.com/question/343682

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The distance from my home to my school is 4 miles. If I can walk at an average rate of 3 miles per hour, how many minutes should it take to walk from home to school?

Answers

Answer:

80 minutes

Step-by-step explanation:

* means multiply

make 1 hour into 60 minutes

3 miles/60 minutes = 4 miles/x minutes

3x = 240

x = 80

In a completely randomized experimental design involving five treatments, 13 observations were recorded for each of the five treatments. The following information is provided.
SSTR = 200 (Sum Square Between Treatments)
SST = 800 (Total Sum Square)
The mean square within treatments (MSE) is _____.
a. 10
b. 600
c. 50
d. 200

Answers

Answer:

[tex]MSE = 10[/tex]

Step-by-step explanation:

Given

[tex]SSTR = 200[/tex]

[tex]SST = 800[/tex]

Required

Determine MSE

This is calculated as:

[tex]MSE = \frac{1}{ddf} * SSE[/tex]

Where:

[tex]SSE = SST - SSTR[/tex]

[tex]ddf \to[/tex] denominator df

So, we have:

[tex]SSE = 800 - 200[/tex]

[tex]SSE = 600[/tex]

To calculate the df, we have:

[tex]r = 13[/tex] --- observations

[tex]n = 5[/tex] treatments

So:

[tex]ddf = Total\ df - Numerator\ df[/tex]

[tex]Total = n*r-1 = 5*13 -1 = 64[/tex]

[tex]Numerator =n - 1 = 5 - 1 =4[/tex]

[tex]ddf =64-4=60[/tex]

So, we have:

[tex]MSE = \frac{1}{ddf} * SSE[/tex]

[tex]MSE = \frac{1}{60} * 600[/tex]

[tex]MSE = 10[/tex]

please help me i need the answers help me please

Answers

Answer:

scientists

Step-by-step explanation:

What is the length of BD Round to one decimal place. Thanks!

Answers

Answer:

2.7

Step-by-step explanation:

ratios help

2.5 : 5.8 :: x : 6.2

2.5/5.8 = x/6.2

solve for x :

x = approx.   2.7

does anyone know the answer

Answers

Answer:

For some reason I cannot open the photo you have provided.

Step-by-step explanation:

Please try to re-upload?

Answer:

upper left...

there are zeros at (x)(x+3) (x-2)

Step-by-step explanation:

Let L be the circle in the x-y plane with center the origin and radius 38. Let S be a moveable circle with radius 8 . S is rolled along the inside of L without slipping while L remains fixed. A point P is marked on S before S is rolled and the path of P is studied. The initial position of P is (38,0). The initial position of the center of S is (14,0) . After S has moved counterclockwise about the origin through an angle t the position of P is:

x = 14cost + 24cos(7/12t)
y= 14sint - 24sin (7/12t)

Required:
How far does P move before it returns to its initial position?

Answers

Answer:

P moves = 70.73 m

Step-by-step explanation:

Given data

Radius = 38

initial position of P = ( 38,0 )

initial position of center S = ( 14,0)

position of P ( after s moved counterclockwise )

:  x = 14cost + 24cos(7/12t)

  y = 14sint - 24sin(7/12t)

Determine how far P moves before returning to its initial position

attached below  is the solution

P moves = 70.74 m


Henry bought a laptop for 4500 the cost of the laptop deprecate by 6% every year.If he decided to sell the laptop after 4 years at what’s price will he sell it

Answers

Answer:

give fufcy UC fugu stuff c

Step-by-step explanation:

zp staff book

If someone earns $10 every 15 minutes, how much do they earn in an hour?

Answers

Answer: 40

Step-by-step explanation:

You multiple 15X4=60

And now multiple 10x4=40

Answer:

40$

Step-by-step explanation:

There are 60 minutes in an hour so if we break it down:

$10 = 15 minutes

$10 = 15 minutes

$10 = 15 minutes

$10 = 15 minutes

-------------------------

Add them together and we get:

$40 = 60 minutes or 1 hour  

Meaning they would make 40$ in 1 hour.

Find mDCAˆ.
A. 92
B. 145
C. 159
D. 113

Answers

9514 1404 393

Answer:

  C.  159°

Step-by-step explanation:

The exterior angle at B is half the difference of the measures of the arcs it intercepts:

  (3x +19)° = 1/2((17x -3)° -91°)

  6x +38 = 17x -94 . . . . . . . . . . multiply by 2, divide by °

  132 = 11x . . . . . . . . . . . . . add 94-6x

  x = 12 . . . . . . . . . . . . divide by 11

Then long arc AD is ...

  arc AD = (17(12) -3)° = 201°

Arc DCA is the rest of the circle:

  arc DCA = 360° -201° = 159°

Find the total surface area of this square based pyramid. 10ft 10ft (in the image)​

Answers

Answer:

300ft^2

Step-by-step explanation:

Surface Area = 2bs + b^2 where s = height of each triangular surface and b = base

Surface Area = 2(10)(10) + 10^2
Surface Area = 2(100) + 100
Surface Area = 200 + 100
Surface Area = 300ft^2

Which proportion correctly shows the equivalence of two fractions?


A)

19∕95 = 57∕76

B)

32∕116 = 9∕29

C)

18∕36 = 72∕144

D)

18∕36 = 144∕72

Answers

Answer:

32/166=9/29 if two ratio are equivalent to other

You are dividing a rectangular garden into 2 equal sections by
placing a wooden plank diagonally across it, from one corner to
the opposite comer. The garden measures 4 feet by 6 feet. What
length diagonal plank should you buy, and why?
Diagonal planks are available in 1-foot increments (you can
buy a 1-foot board, or a 2-foot board, or a 3-foot board, and
so on...)
• You can cut the plank down from the size you buy to the
exact size, but you want to waste as little wood as possible.

Answers

Answer:

You can cut the plank down from the size you buy to the

exact size, but you want to waste as little wood as possible.

Write an equation of the line that passes through the pair of points (5, 8) and
(9, 16).

Answers

Answer:

D: y = 2x - 2

Step-by-step explanation:

1. [tex]\frac{16-8}{9-5}[/tex] = 2

2. y = 2x + b

3. Insert the points into the equation: 8 = 10 + b

4. b = -2

5. y = 2x - 2

Answer:  Choice D)  y = 2x-2

=======================================================

Explanation:

Apply the slope formula

m = (y2-y1)/(x2-x1)

m = (16-8)/(9-5)

m = 8/4

m = 2

Then use this slope, along with another point such as (x,y) = (5,8) to find b

y = mx+b

8 = 2*5+b

8 = 10+b

8-10 = b

-2 = b

b = -2

Or you could use the other point (x,y) = (9,16)

y = mx+b

16 = 2*9+b

16 = 18+b

16-18 = b

-2 = b

b = -2

Either way, we get the same y intercept.

So because m = 2 is the slope and b = -2 is the y intercept, we go from y = mx+b to y = 2x-2

-------------------

To help verify the answer, note how plugging x = 5 leads us to...

y = 2x-2

y = 2*5 - 2

y = 10-2

y = 8

So x = 5 and y = 8 pair up together. This verifies (5,8) is on the line.

Through similar steps, you should find that the input x = 9 leads to the output y = 16. So that would confirm (9,16) is also on the line, and fully confirm the answer.

find x

thank you thank you thank you!!​

Answers

Answer:

Step-by-step explanation:

x=120°

i just need the answer no explanation

Answers

The answer is the second choice

Help me please on this question

Answers

Answer:

a) upward

b) x = -2

c) -2, 1

d)

none

y = 5

Step-by-step explanation:

a) I think that is clear and speaks for itself.

b) axis of symmetry : around what line can this figure be considered as "mirrored", so that it looks like how it looks ?

x = -2 is a line/axis parallel to the y-axis (vertical) that does the figure into 2 halves that are the mirrored images of each other.

c) the extreme point. the point with a tangent with slope=0 (a flat line). there is only one. at x=-2. and the y-value is 1.

d) there is no intercept with the x-axis at all.

and the intercept with the y-axis is at y=5.

The measure of ∠1 is 39°. What is the measure of ∠2?

Answers

Answer:

141

Step-by-step explanation:

if the sum of the two angles equals 180 subtract 39 from 180 to get the remainder of 141 which is angle 2

What system of equations is shown on the graph below

Answers

Answer:

A.

Step-by-step explanation:

x-2y=4 has a x-intercept of 4, a slope of 1/2, and a y-intercept of -2. 2x+y=4 has a x-intercept of -2, a slope of 2, and a y-intercept of -4.

!!!HELPPP PLEASEEE!!! For this problem I thought it meant to subtract 0.1492 - 0.1515 = -0.0023 however my answer was incorrect. How do I solve this problem then? Help Please!

Answers

Answer:

0.1492-0.1515= -0.0023

Find f(2) if f(x) = (x + 1)2.
9
6
5

Answers

6 just trust me bro I’m a major in math
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