please help this is my last question

1. 83.92

2.15.88

3. 19.66

Answer:A

Step-by-step explanation:

Answer:

answer is A

Step-by-step explanation:

yes A

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:

  2436

Step-by-step explanation:

The sum of n terms of an arithmetic series is given by the formula ...

  Sn = (n/2)(2a +d(n -1))

where a is the first term, and d is the common difference.

__

This series has ...

  a = 46

  d = 53 -46 = 7

  n = 21

So, the desired sum is ...

  S21 = (21/2)(2(46) +7(20)) = 2436

The sum of the first 21 terms is 2436.

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 :)

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

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.

https://brainly.com/question/15016913

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Answer:

  x = 4

Step-by-step explanation:

The base angles of an isosceles triangle are congruent, as shown in the figure.

Equating their measures, we have ...

  ∠A = ∠C

  8x -7 = 25 . . . . substitute the given expressions

  8x = 32 . . . . . add 7

  x = 4 . . . . . . divide by 8

Answer:

x = -3 2/3

have a great day

Answer:

x = -3 2/3

Step-by-step explanation:

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:

D. Distance

Step-by-step explanation:

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

- AKIA

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]

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:

53 meters

Step-by-step explanation:

5300 / 100 = 53

because yes

Answer:

1 AM

Step-by-step explanation:

9AM(start time) to 9PM = 12 hours + the other 4 Hours, 10PM, 11PM, 12PM, 1AM(end time).

Answer:

D

Step-by-step explanation:

Answer:

It is increasing

The y-intercept is (0, 3).

The domain of F(x) is all real numbers.

Answer: 234 in sq.

Step-by-step explanation: Volume = length times width times height.

13 x 9 x 2 = 234 in sq.

Hope this helps.

Answer:

6 inches

Step-by-step explanation:

105÷35=3

3x2=6

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

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:

https://brainly.com/question/9892082

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Answer:

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

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:

she only has saved 28 3 times according to the data

Step-by-step explanation:

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:

(-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!