Kara has 10 books on a shelf and decides to move 3 of them to an empty shelf. In how many different ways can the empty shelf be filled?

Answers

Answer 1

The empty shelf can be filled in 120 ways

The total number of books is

[tex]n = 10[/tex]

The number of books to move is:

[tex]r = 3[/tex]

To fill the empty shelf with three books, we make use of the following combination formula

[tex]^{n}C_r = \frac{n!}{(n - r)!r!}[/tex]

So, we have:

[tex]^{10}C_3 = \frac{10!}{(10 - 3)!3!}[/tex]

Evaluate the expression

[tex]^{10}C_3 = \frac{10!}{7!3!}[/tex]

Expand

[tex]^{10}C_3 = \frac{10 \times 9 \times 8 \times 7!}{7! \times 3\times 2 \times 1}[/tex]

Cancel out the common factors

[tex]^{10}C_3 = \frac{10 \times 9 \times 8}{3\times 2 \times 1}[/tex]

Evaluate the products

[tex]^{10}C_3 = \frac{720}{6}[/tex]

Divide

[tex]^{10}C_3 = 120[/tex]

Hence, the empty shelf can be filled in 120 ways

Read more about combinations at:

https://brainly.com/question/11732255


Related Questions

Susan estimated she would spend $250 on school clothes at the start of the school year. She actually ended up spending only $230. What was her percent of error in her calculations?

Answers

Answer:

8.7%

Step-by-step explanation:

the formula for  % error is = [ (approx. - exact ) / exact ] x 100

so, we know the approx value was 250 while the exact one is 230

thus; [ ( 250-230 ) / 230 ] x 100

= 8.7%

Use the net to find the surface area of the rectangular prism

Answers

Answer:

52

Step-by-step explanation:

what is the product
4/6 x 9

13/16

36/54

3

6​

Answers

the answer is 6! have a good day

I NEED HELP!
The function f(x) is a quadratic function and the zeros of f(x) are - 2 and 5. The y-intercept of f(x) is 30. Write the equation of the quadratic polynomial in standard form.
f(x)=___________

Answers

Answer:

Step-by-step explanation:

First of all you have to put the zeros into factor form.

y1 = (x + 2)(x - 5)

Notice that the x changes sigh. You say that the zeros are -2 and  5. To get y1 to go to zero, you must make x the opposite sign of what you are given.

Now you have to expand the factored form to get the standard form

y = x^2 + 2x - 5x - 10

y = x^2 - 3x - 10

That's not the right answer.

f(0) = 30 but you have - 10 at the end so you have to multiply the factored form by - 3

-3(f(x)) = -3(x + 2)(x - 5)

-3(f(x)) = -3(x^2 - 3x - 10)

f(x) = -3x^2 + 9x + 30    

f(0) = -3(0)^2 + 9(0) + 30

f(0) = 30

The quadratic still has roots of (x +2)(x - 5) but that 3 makes the y intercept = 30.

See the graph below.

Bruce drewa scale of a resturaunt the scale he used was 1 milimeter 10 meters the resteraunt kitchen is 3 milimeters long in the drawing how long is the actual kitchen

Answers

Answer: 30 meters.

Step-by-step explanation:

Since the scale used by Bruce in the drawing that she made is:

1 milimeter = 10 meters

If the restaurant kitchen is 3 milimeters long in the drawing, the length of the actual kitchen will then be:

1/3 = 10/x

Cross multiply

1 × x = 3 × 10

x = 30

Therefore, the actual length is 30 meters.

The topology taxi company charges 2.60 for the first quarter of a mile and 0.36 for each additional fifth of a mile. Find a linear function which models the taxi fare F as a function of the number of miles driven m

Answers

Answer:

The piecewise function for the taxi fare is:

[tex]F(t) = 2.60\cdot \left(\frac {m}{0.25}\right) ,\, 0\,mi\le m \le 0.25\,mi[/tex]

[tex]F(t) = 2.60 + 0.36\cdot \left(\frac{m}{0.2} \right)[/tex], [tex]m > 0.25\,mi[/tex]

Step-by-step explanation:

We must use the following piecewise function:

(i) The Topology Taxi Company charges 2.60 for the first quarter of a mile:

[tex]F(t) = 2.60\cdot \left(\frac {m}{0.25}\right) ,\, 0\,mi\le m \le 0.25\,mi[/tex] (1)

Where:

[tex]F(t)[/tex] - Taxi fare, in monetary units.

[tex]m[/tex] - Number of miles driven, in miles.

(ii) And 0.36 for each additional fifth of a mile:

[tex]F(t) = 2.60 + 0.36\cdot \left(\frac{m}{0.2} \right)[/tex], [tex]m > 0.25\,mi[/tex] (2)

Subtracting fractions with unlike denominators

Answers

improper fraction - 37/15 or mixed fraction - 2 7/15

Find the area of the parallelogram. base is 10 and height is 8

Answers

Answer:

80

Step-by-step explanation:

8*10

help me please?
The function ƒ(x) = 2x + 1 indicates:
a downward shift of 1 unit.
a shift of 1 unit to the left
an upward shift of 1 unit.
None of these choices are correct.

Answers

Upward shift of one unit

Confused!? Pls, help me correctly and quickly.

Answers

Answer:

The new figure would be 9 by 15

Step-by-step explanation:

please help me with the question​

Answers

2/3x -1/5 > 1
+1/5 > 1 + 1/5 add 1/5 to the both sides
2/3x > 6/5
(3/2) * (2/3x) > (3/2)*(6/5) multiply both sides by 3/2
X > 9/5

The sum of -9 and 18/2

Answers

Answer:

0

Step-by-step explanation:

Sum means addition so:

-9 + 18/2

(18/2 = 9)

-9 + 9

0

Answer: 0

Step-by-step explanation: The answer I got was 0. I'm assuming that 18/2 is 18 divided by 2. 18 divided by 2 is 9 and if you add a positive and a negative its like subtracting. 9-9=0 so the answer is 0.

Tim washed 15 cars in 3hours.how many cars can he wash In 7 hours?​

Answers

Answer:

35 cars

Step-by-step explanation: ok so here is how you do it you divide 15 and 3 to find out how much cars Tim washed in one hour so in this case we got 5 then we multiply the hours by 7 and we get 35 cars

Answer:

I believe the answer is 35.

Step-by-step explanation:

15+15=30

30+5=45

1 hour = 5 cars

3 hours = 15 cars

6 hours = 30 cars

7 hours = 35 cars

15 divided by 3 = 1

so yeah hope this helps you.

Which two of the following have the same value as 50.96?
Choose 2 answers:

Answers

Answer:

A and C

Step-by-step explanation:

A: 5 tens = 50

9 tenths = 0.9

6 hundreths = 0.06

= 50.96

C: 5*10 = 50 + 9 * 1/10 = 0.9 + 6 * 1/100 = 50.96

Triangle ABC is taken to triangle ABC by a dilation. Which of these scale factors for the dilation would result in an image that was larger than the original figure?

A)3/5
b)13/17
c)1
D)4/3​

Answers

Answer:

D

Step-by-step explanation:

you would see this as correct because it has a larger numerator than its denominator.

I think D but I'm not aure

SOMEONE PLEASEEEE HELPPPP?!!?!?!?!!?!?!??!

Answers

(4,5) find x then find y. Hope this helps!

What is the area of the trapezoid below?

Answers

Answer:

A = 180 units²

Step-by-step explanation:

The area (A) of a trapezoid is calculated as

A = [tex]\frac{1}{2}[/tex] h (b₁ + b₂ )

where h is the perpendicular height and b₁, b₂ the parallel bases

The triangle on the left is right with h = 24 (7- 24- 25 triangle )

Here h = 24, b₁ = 4 and b₂ = 7 + 4 = 11 , then

A = [tex]\frac{1}{2}[/tex] × 24 × (4 + 11) = 12 × 15 = 180 units²

Write the number 0.000037 in scientific notation

Answers

Answer:

3.7 x 10^-5

Step-by-step explanation:

A circle with a radius equal to 12 feet.

Answers

Answer:

What do you mean a radius equal to 12 feet? What is your question?

Step-by-step explanation:

A nature park has two ticket plans. With one plan, you pay a $24 yearly membership fee plus $8
for each visit. The other plan has no membership fee, but you pay $14 for each visit. Isaac is on
the first ticket plan and Maddie is on the second ticket plan. After how many visits will they each
have paid the same amount
F 5
G6
H4
J 3

Answers

Answer:

G6

Step-by-step explanation:

Which pictures below show pure substances?

Answers

The answers are A,B, and C

Figure AAA maps to figure BBB with a scale factor of 0.750.750, point, 75.

Answers

Answer:

7.5

Step-by-step explanation:

x=10*0.75 = 7.5

note that b is smaller than a

. Find the indicated term of the arithmetic sequence.

Find a_23 in the sequence -18,-34,-50,-66,…

Answers

Answer:

Hello . ♡

The answer to your question is : −370 .

Step-by-step explanation:

Hope this helps u ;)

Oi lend a hand here? Math isn't my thing :P​

Answers

x is less than or equal to 5, really simple

Answer:

C

Step-by-step explanation:

Help me out here plz

Answers

Answer:

I think that it would be [tex]28^{2}[/tex] cm

Step-by-step explanation:

8 x 7 = 56

56/2 = 28

Spider Rock is located in Canyon de Chelly National Park in Arizona. A surveyor stands 370 feet from the base of Spider Rock. From a point 5.5 feet above the ground, he measures the angle of elevation to the top of Spider Rock to be 65°. According to the surveyor's measurements, what is the height of Spider Rock? Round your answer to the nearest tenth. A. 178.0 ft. B. 340.8 ft. C. 413.7 ft. D. 799.0 ft.

Answers

Answer:

799 feet

Step-by-step explanation:

We solve using the Trigonometric function of Tangent.

tan theta = Opposite /Adjacent

From the above question, we have the height of the surveyor = 5.5 feet

theta = Angle of elevation = 65°

Adjacent = 370 feet

Let Opposite = height + height of spider rock

tan 65° = h - 5.5 /370 feet

Cross Multiply

tan 65° × 370 feet = h - 5.5

793.46756059 feet = h - 5.5

h = 793.46756059 feet + 5.5

h = 798.96756059 feet

Approximately = 799 feet

The height of the Spider rock = 799 feet

A rectangular prism has a length of 4 inches, a height of 5 inches, and a width of 19 inches. What is its volume, in cubic inches?

Answers

Answer:

380 cubic inches

Step-by-step explanation:

The basic formula is length x width x height, so it's pretty simple, you just do 4 x 19 x 5! The order doesn't matter as long as it's just the length worth and height

I, sometimes do length x width, then use the answer for that and multiply it by the height (So that I can break it down)

4) x/5 =2
plz explain

Answers

Step 1: Multiply both sides by 5.

4x = 2
5
(4x) * (5) = (2) * (5)
5

4x = 10

Step 2: Divide both sides by 4.

4x = 10
4 4

Answer:

x = 5
2

Write the equation of each circle. center at (-4, 3), radius 9

Answers

Answer:

(x-h)²+(y-k)²=r²

putting respective value

(x--4)²+(y-3)²=9²

(x+4)²+(y-3)²=81

Answer:

(x + 4)^2 + (y - 3)^2 = 9^2

Step-by-step explanation:

Here our center is at (-4, 3), so h = -4 and k = 3.  Radius, r, is 9.

Insert these values into the standard equation of a circle centered at (h, k) with radius r:

(x - h)^2 + (y - k)^2 = r^2 becomes:

(x + 4)^2 + (y - 3)^2 = 9^2

HELP PLEASE I DONT KNOW WHAT TO DO

Answers

Answer:

5, -10, 10

Step-by-step explanation:

a “step“ can’t be negative so we can say that we move twice to left 5 spaces

a positive number multiplied by a negative number gives as result a negative number. In this case -10

the opposite of a number is the same number in absolute value with a opposite sign. In this case 10

Other Questions
Which of the stores below does the following sentence describe?Vous achetez du bon pain ici.O A. La boulangerie.B. La poissonnerie.O C. La charcuterie.O D. La boucherie. Help me! Who ever gets to answer and has the best answer gets brainliest (very easy!) Assigning manufacturing overhead costs and other indirect costs is called a: What is the difference between PowerPoint and Outlook?PowerPoint is a presentation program; Outlook is a personal information management application.Outlook is a presentation program; PowerPoint is a personal information management application.PowerPoint is a program that lets you create, edit, format, and print written documents; Outlook is a computer application that uses a grid system to organize and manipulate data.Outlook is a program that lets you create, edit, format, and print written documents; PowerPoint is a computer application that uses a grid system to organize and manipulate data. Which set of vertices forms a parallelogram? A. A(2,4), B(3,3), C((6,4), D(5,6). B. A(-1,1), B(2,2), C(5,1), D(4,1)C. A(-5,-2), B(-3,3), C(3,5), D(1,0)D. A(-1,2), B(1,3), C(5,3), D(1,1) How many grams is 2.393 x 10^24 atoms of O?70.45 g O140.9 g O63.58 mole O63.58 g O Complete The Sentences: Natural selection is the process by which organisms that have... {starts with b}traits are more likely to... {starts with s}and... {starts with r} (580+393,873,532) -(353,453x4,543)657 You have one type of nut that sells for $4.50/lb and another type of nut that sells for $8.00/lb. You would like to have 28 lbs of a nut mixture that sells for $7.80/lb. How much of each nut will you need to obtain the desired mixture?You will need lbs of the cheaper nutand lbs of the expensive nut. Can somebody who knows how to do this plz help answer these questions correctly (only if u done this before) thx :3WILL MARK BRAINLEST WHOEVER ANSWERS FIRST :DDDD The three main stages to the memory process are encoding, storage, and retrieval. A.True B.False What happens to the equilibrium price and quantity in the market for orange juice in Florida if a hurricane causes a seasonal orange shortage and the price of apple juice falls substantially. Select the correct answer below: the equilibrium price of orange juice will fall the equilibrium price of orange juice will rise the equilibrium quantity will rise the equilibrium quantity will fall what does hobbes mean when he says, we (as citizens should lay down our right to everything? is he saying we should allow others to have more power or rights over us help! look at photo to answer What does the quote ''Look deep into nature, and then you will understand everything better'' mean? Sin(x)=sqrt3/2 solutions of True or False. Write letter A is the statement is true. If the statement is incorrect, write letter B.41. Plot is an element of short story referring to angle in which story is narrative.42. The Story of Bathala is an example of legend.43. The moral or value is the writer's message.44. A poet recreates an experience through words and phrases that appeal to the five senses.45. The narrator acts as if he knows everything that happens including the thoughts of the characters is calledThird Person Omniscient Point of View.46. "Life is a stage." is an example of metaphor.47. Man in the tub is a kind of plou wherein a straightforward decision is constructed followed by a flash of realization.48. Poetic sound is the result of the combination of poetic elements,49. Flashback is the narration of the past events that come into a person's mind.50. Antithesis Involves a contrast and similarity of words or ideas.pasagot pls How many moles of ammonia are produced due to the reaction with two moles of nitrogen? Which of these is a set of inputs and outputs for the function f(x) = 2x + 4A(1,2), (2,5), (3,8)B.(1,4), (2,6), (3,7)(1,5), (1,8), (1, 10)D(1,6), (2,8), (3, 10) What is the length of JK, to the nearest tenth of a millimeter? 4.5 mm 5.6 mm 8.3 mm 19.9 mm A horizontally-aligned scalene triangle J K L. Side J L is labeled as 3 millimeters. Side L K is labeled as 5 millimeters. Angle L is labeled as 62 degrees.