Help pls (picture included)

See the link in comments (or if it gets deleted, look up "partial derangement"). The number of ways in which exactly [tex]k[/tex] items from a pool of [tex]n[/tex] items can be rearranged such that only these [tex]k[/tex] items are in their original positions is

[tex]R(n,k) = \dbinom nk \, !(n-k)[/tex]

where [tex]!(n-k)[/tex] is the so-called sub-factorial that satisfies the relation

[tex]!n = \left\lfloor \dfrac{n!+1}e \right\rfloor[/tex]

and [tex]\lfloor x \rfloor[/tex] denotes the floor or greatest integer function of [tex]x[/tex], i.e. the greatest integer smaller than or equal to [tex]x[/tex].

There are 25! ways of handing back exams with no extra constraint.

There are [tex]R(25,23)[/tex] ways of handing back 23 exams to their original owners and 2 exams otherwise, and

[tex]R(25,23) = \dbinom{25}{23} \, !(25-23) = 300\left\lfloor\dfrac{2!+1}e\right\rfloor = 300[/tex]

Then the probability of returning 23 exams correctly and 2 exams swapped is

[tex]\dfrac{300}{25!} \approx \boxed{5.17\times10^{-22}}[/tex]

Answer:

2048 or D

Step-by-step explanation:

We can use the formula c=(pi)(d)

replace 6,430.72 with c!

c=(pi)(d)

6,430.72=3.14*d

- Divide both sides by 3.14 -

d = 2048

Answer:

It's A :)

Step-by-step explanation:

30/2 is 15

15 is a whole number so it applies to everything except for irrational numbers

Hope this helps :)

Step-by-step explanation:

f(x) = x² + 2 XER ... Range of f(x) = (2, ∞)

x² ≥ 0

x²+2 ≥ 2

Applying the tangent theorem, the length of PX in the circle is: B. 13 cm.

The tangent theorem states that a right angle is formed at the point where the tangent meets with the radius of a circle on the circle's circumference.

Based on the tangent theorem, triangle PYX is a right triangle. Use Pythagorean theorem to find PX.

PX = √(12² + 5²)

PX = 13 cm.

Learn more about the tangent theorem on:

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The speed that marina can run from the given parameters is; 4 miles per hour

Let x be Marina's speed running.

Marina's speed biking is x + 9.

Thus, the time she spent is calculated as;

19.5/(x + 9) = 6/x

Cross Multiply to get;

19.5x = 6(x + 9)

19.5x = 6x + 54

Solving this gives;

x ≈ 4 mph

Thus, Marina can run at a speed of 4 miles per hour.

Read more about Algebraic Problems at; https://brainly.com/question/1491745

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4 miles per hour:A

Step-by-step explanation:

on edge

Answer: Scalene means "a triangle that has three unequal sides"

therefore it is D

Answer:

Shade in 5 parts of the 10 strip.

Step-by-step explanation:

I didn't get an image but what I think the problem looks like is this, 10 empty strips, but just fill in 5, then it looks like the second image.

Answer:

5/13

Step-by-step explanation:

There are 20 girls, and 32+20 = 52 learners.

Ratio give us 20/52

After simplifying: 5/13

Answer:

the sum of the measures of it's angles is 180

The weights that represent 90% of the weight of a four years old boy will be 44.58

The z-score is a statistical evaluation of a value's correlation to the mean of a collection of values, expressed in terms of standard deviation.

The weights of four years old boys are normally distributed with a mean of 38 pounds and a standard deviation of 4 pounds.

The value of the z-score at 90% will be 1.645

Then the weights that represent the 90% of the weight of a four year old will be

1.645 = (x - 38)/4

6.58 = x - 38

      x = 44.58

More about the normal distribution link is given below.

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By using trigonometric relations, we will see that the distance to the fire is .173.21 ft

Here we can compare this with a right triangle. We know that one angle on the right triangle is 30°, and the adjacent cathetus to that triangle is 150ft.

Now, we want to find the hypotenuse of said triangle, which is the distance to the fire.

So we can use the trigonometric relation:

cos(a) = (adjacent cathetus)/(hypotenuse).

Replacing what we know, we get:

cos(30°) = 150ft/hypotenuse

hypotenuse = 150ft/cos(30°) = 173.21 ft

So the distance to the fire is 173.21 ft

If you want to learn more about right triangles:

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Answer:

1471.15

A = πrl+πr²

l = [tex]\sqrt{r^2+h^2}[/tex]

A = [tex]\pi r(r+\sqrt{h^2+r^2} ) = \pi * 13 * (13 + \sqrt{19^2+13^2} )[/tex]  ≈ 1471.15

Answer:

D

Step-by-step explanation:

Answer:

D. Distance

Step-by-step explanation:

Distance is measured to determine the winner of the shot-put competition

- AKIA

Answer:

x⁷⁶ + 2401

Step-by-step explanation:

When an exponent is raised to another exponent, the two exponent values are multiplied. When a number is raised to an exponent, the number is multiplied by itself that many of times.

(x¹⁹ + 7)⁴  ---->

x⁽¹⁹ ˣ ⁴⁾ + 7⁴  --->  

x⁷⁶ + (7 x 7 x 7 x 7)  --->

x⁷⁶ + 2401

1. 83.92

2.15.88

3. 19.66

the answer is 153.86 ft squared

= the formula for the area of a circle is A=πr2

= area = pi x radius squared

= the radius is 7 feet, square that to get 49

= multiply 49 by pi to get the area: 153.86 square feet

153.86 ft squared

Answer:

153.86 ft squared

Step-by-step explanation:

As per given question we have provided that :

We need to find :

Here's the required formula :

[tex]{\dashrightarrow\sf{A = \pi {r}^{2}}}[/tex]

Substituting all the given values in the formula to find the area of circular pool :

[tex]{\dashrightarrow{\sf{Area = \pi {r}^{2}}}}[/tex]

[tex]{\dashrightarrow{\sf{Area = 3.14{(7)}^{2}}}}[/tex]

[tex]{\dashrightarrow{\sf{Area = 3.14{(7 \times 7)}}}}[/tex]

[tex]{\dashrightarrow{\sf{Area = 3.14{(49)}}}}[/tex]

[tex]{\dashrightarrow{\sf{Area = 3.14 \times 49}}}[/tex]

[tex]{\dashrightarrow{\sf{Area = 153.86}}}[/tex]

[tex]\star{\underline{\boxed{\sf{\red{Area = 153.86 \: {ft}^{2}}}}}}[/tex]

Hence, the area of circular pool is 153.86 ft².

[tex]\rule{300}{1.5}[/tex]

Answer:

12

Step-by-step explanation:

if x = 3

and y = 4

3 + 4 + 5 = 12

what grade is this

Answer:

The numbers less than 50 (A) = 4

Total numbers (S) = 14

Probability students below 50 = 4÷14

Step-by-step explanation:

That is the correct answer of it.

Answer:

- attached graph

- Horizontal Asymptote: y = 5

- twon whole number points are (4,4) and (5,1)

Step-by-step explanation:

- Exponential functions have a horizontal asymptote. The equation of the horizontal asymptote

y = -4^(x-4) + 5

  = -4^(4-4) + 5

  = -4^(0) + 5

  = -1 + 5

  = 4

y = -4^(x-4) + 5

  = -4^(5-4) + 5

  = -4^(1) + 5

  = -4 + 5

  = 1

Answer:

she only has saved 28 3 times according to the data

Step-by-step explanation:

Answer:

1. x=44°

2.5x=50°

3x=30°

Step-by-step explanation:

1) 46°+x=90°

x=90-46= 44°

X= 44°

2) 5x+100°+3x=180°

8x+100=180

8x=180-100

8x=80

x=80/8

x=10

substitute the value of x in '3x' and '5x'

3*10=30

5*10= 50

Answer:

(-1,-2)

Step-by-step explanation:

The given coordinates are ,

G ( 4 , 10)

H ( -2 , -6)

Midpoint can be calculated by finding the mean of x coordinates and y coordinates . As ,

→ Midpoint = ( 4-2/2 , 10-6/2)

→ Midpoint = ( -2/2 , -4/2 )

→ Midpoint = ( - 1 , -2)

To find out the midpoint,here's the formula: ((x1+x2)÷2 , (y1+y2)÷2)

Thus,the midpoint of QS is

((4+(-2))÷2 , (10+3)÷2)

=(1 , 13/2)

hope it helps!