o keep the spectators out of the line of flight at an air show, the ushers arranged the show's seats in the shape of an inverted triangle. Kevin, who loves airplanes, arrived very early and was seated in the front row, which contained one seat. The second row contained three seats, and those filled very quickly. The third row contained five seats, which were given to the next five people who came. The next row contained seven seats. This seating pattern continued all the way to the last row, with each row containing two more seats than the previous row. All 20 rows were filled. How many people attended the air sh

Answers

Answer 1

Answer:

400 people attended the air show.

Step-by-step explanation:

Arithmetic sequence:

An arithmetic sequence has the following general equation:

[tex]a_n = a_1 + d(n-1)[/tex]

In which [tex]a_n[/tex] is the nth term, [tex]a_1[/tex] is the first term and d is the common difference between the terms.

The sum of the first n terms of an arithmetic sequence is given by:

[tex]S_n = \frac{n(a_1+a_n)}{2}[/tex]

In this question:

First row 1 seat, second 3 seats, 3rd 5 seats and so on.

So we have the following arithmetic sequence:

{1,3,5,7,9,...}

So [tex]a_1 = 1, d = 9 - 7 = 7 - 5 = ... = 2[/tex]

So

[tex]a_n = 1 + 2(n-1)[/tex]

All 20 rows were filled. How many people attended the air show?

Sum of the 20 terms of the progression. So

[tex]S_{20} = \frac{20(1+a_{20})}{2} = 10(1+a_{20})[/tex]

The 20th term is:

[tex]a_{20} = 1 + 2(20-1) = 1 + 2*19 = 1 + 38 = 39[/tex]

So

[tex]S_{20} = 10(1+a_{20}) = 10(1 + 39) = 10(40) = 400[/tex]

400 people attended the air show.


Related Questions

Simplify 3(r+5)-4r help me pls NOW

Answers

Answer:

-r + 15

Step-by-step explanation:

3r + 15 - 4r =

-r + 15

Hope that helps!

State a cubic or quartic function with the least degree possible in intercept form for the given graph. Assume that all x-intercepts are integers, and that the constant factor a is either 1 or −1.
Enter the correct value in the box to answer the question.
y= ?

Answers

Answer:

y = [tex]-x^{3} - 2x^{2} + 5x + 6[/tex]

Step-by-step explanation:

The function will be cubic.  The x-intercepts are -4, -1, and 2

The constant factor is -1 because the graph falls on the right.  So,

y = -(x + 4)(x + 1)(x - 2)

y = -[tex]x^{3} -2x^{2} + 5x +6[/tex]

What is the value of x in the following triangle?

Answers

Answer:

x=-10/3

Step-by-step explanation:

Answer: x = 17

Step-by-step explanation:

Triangle angle sum theorem states the three interior angles of a triangle sum to 180 degrees. Add all of the angles together and set equal to 180 to solve for x.

(3x)+(6x+10)+x= 180. Combine like terms.

10x + 10= 180. Subtract 10 from both sides.

10x = 170. Divide both sides by 10.

X = 17

PLZZZ HELP ME I DON'T GET THIS

Answers

Question: 6(10+z+3)

Step 1: multiply 6 to the 10
6x10=60

Step 2: multiply 6 to the z
6xz= 6z

Step 3: multiply 6 to the 3
6x3=18

Step 4: add the products (solutions) together:
60+6z+18= 78+6z (they are not like terms so we can’t add them together.

I hope this helps and gives you a clear idea of how to do these types of problems.
Let me know if you have any other questions.
Good Luck!

(A Brainliest would be very appreciated! ❤️)

3n + 2 + 5 = 4
NEED ASAP

Answers

Step-by-step explanation:

given

3n + 2 + 5 = 4

3n + 7 = 4

3n = 4 - 7

3n = - 3

n = - 3 / 3

n = -1

Hope it will help :)❤

f(x) = -22 + x + 14
Find f(2)

Answers

Answer:

sln

f(x) =-22+x+14 put 2 in x

f(2)=-22+2+14

f(2) =38

Here is some record-keeping from a coffee shop about their paper cups. Cups are delivered 2,000 at a time. How many paper cups are left at the end of the day on Wednesday?

Answers

Answer:

1748

Step-by-step explanation:

Tuesday + Wednesday - Monday

1748 is the correct answer

What type of angles are ∠4 and ∠6?

I’ll mark brainiest

Answers

Answer:

angle 4 and angle 6 are ALTERNATE INTERIOR angles

Answer:

alternate interior

Step-by-step explanation:

hope it helps ;)

al comprar una estufa de 5579 le cobran 9%de su costo extra para llevarlo a domicilio cuanto se pagará en total si la estufa será llevada​

Answers

Answer:

6081.11

Step-by-step explanation:

Para resolverlo debes usar la regla de 3 simples:

La estufa cuesta $5,579 y te cobrarán el 9% para llevarlo a domicilio para eso realizarás esta operación

5579  =   100%

  X    =       9%

Ahora debes multiplicar 5579 x 9 = 50211

Ahora debes dividirlo entre 100  50211 ÷ 100 = 502.11 entonces el 9% es $502.11

Para terminar debes sumar el precio de la estufa y lo que cuesta llevarlo a domicilio     5579 + 502.11 = 6081.11

En total pagará $6081.11

How many zeros does the equation x^5 – 11^4+ 7 have?

Answers

Answer:

5

Step-by-step explanation:

No. of Zeroes or Roots is equal to the degree of polynomial. Here, the degree of polynomial of the equation is 5. Hence, 5 Zeroes are possible.

At a scrapbooking party, guests brought a certain number of photographs to use, based on
how many pages they will be assembling. Ellie plans to assemble 4 small pages and 7 large
pages and brought a total of 22 photographs to use. Bridgette brought 30 photographs,
which is enough to assemble 8 small pages and 7 large pages. Assuming that the number of
photographs on a page remains constant, how many photographs fit on a small page and a
large page?
A small page can fit
photographs, and a large one can fit
photographs.

Answers

Answer:

A small page can fit 2 photographs, and a large on can fit 2 photographs.

Step-by-step explanation:

Let the number of photographs on the small page be represented by m and that of large one by n.

Since the number of photographs on a page remains constant, then;

4m + 7n = 22 ........... 1

8m + 7n = 30 .......... 2

Multiply equation 1 by 2, and 2 by 1 to have;

8m + 14n = 44 ....... 3

8m + 7n = 30 ......... 4

subtract equation 4 from 3,

7n = 14

n = 2

Substitute the value of n in equation 1

4m + 7(2) = 22

4m + 14 = 22

4m = 8

m = 2

m = 2, n = 2

Therefore, a small page can fit 2 photographs, and a large on can fit 2 photographs so that the number of photographs n a page is constant.

I need help on this problem if it's possible can you walk me through how to do it?​

Answers

Answer:

Just subtract the area of two triangles from the area of the rectangle

Step-by-step explanation:

Answer:

149 ft^2

Step-by-step explanation:

First, figure out the whole square area.

Which is 9 1/4 x 20 = 185

One triangle is 6 x 6 x .5 because the formula of a triangle is A=bh1/2.

Triangle=18

There are two triangles so its 36.

185-36 = 149

Is this helpful? Tell me if you need me to further explain.

carolette is making necklace's in blue and orange her ratio of blue beads to orange beads are 3 to 2 how many beads will carolette need for a necklace of 60 beads

Answers

Answer:

Carlotta needs 24 orange beads for her necklace.

Step-by-step explanation:

For each necklace, the ratio of blue beads to orange beads is 3 to 2. or 3:2

Total beads given to make a necklace is = 60

Let the number of orange beads be = x

The ratio is 2 orange beads out of 5 total beads

So, we can represent the ratio as:

x=24

Hence, Carlotta needs 24 orange beads for her necklace.

Blue beads needed =  

We can also check the ratio for blue beads to orange beads:

Divide by 4, we get

Divide by 3, we get

 ...... (the given ratio)

Therefore, Carlotta needs 24 orange beads for her necklace

Seven times the difference of a number and 7

Answers

Answer:

7 (x-7) or 7x-49

7x-49 would be the answer

What is the final value?
Initial value: 170
Increase: 8%

Answers

Answer:

183.6

Step-by-step explanation:

170, percentage increased by 8% (percent) of its value = 183.6

Answer:

183.6

Step-by-step explanation:

170 divided by 100 = 1.7 multiplied by 8 = 13.6 + 170 = 183.6

Every square is a rhombus.

True
False

Answers

Answer:

false

a rhombus only has 4 equilateral sides and a square has 4 equilateral sides and all interior angles are right angles therefore that question is false

false, that is not true

Find the amount of time. I = $54, P = $800, r= 4.5% The amount of time is years.​

Answers

Answer:

1.5 years

Step-by-step explanation:

I = prt

54 = 800(.045)t

54 = 36t

t = 54/36

t = 1.55

Answer:

The amount of time is 1.5 years

Write each of the following percents in words. a. 5% b. 34% c. 143% d. 500%

Answers

Answer:

5%=Five percent

34%=Thirty four percent

143%=One hundred forty three percent

500%=Five hundred percent

Hope it helps

Have a great day : )

Mark me brainiest if it had helped you

The relationship is “hours multiplied by
equals the number of dogs.”

Answers

Answer:

3

Step-by-step explanation:

Answer:

The relationship is “hours multiplied by  

3

equals the number of dogs.”

Step-by-step explanation:

Enter the product as a mixed number ​

Answers

9514 1404 393

Answer:

  10 1/5

Step-by-step explanation:

3 × 3 2/5 = 3(3) +3(2/5) = 9 +6/5 = 9 + 1 1/5

  = 10 1/5

ng 20-21
POSSIBLE POINTS: 10
In the school store, you can buy 20 calculators for $120. You want to buy 5 calculators. The table below represents the cost of different numbers of
calculators. Complete the table and explain the mathematical process you used to determine the cost of 5 calculators.

Answers

you would spend $30

Step-by-step explanation:

if 20 calculator cost 120 then you would divide 20 by 120 which would give you 6 dollars per calculator then you would multiply that by 5 which would give you a $30 for five calculators.

Answer:

where is the table?

I am just telling you how to get the cost of 5 calculators...

Step-by-step explanation:

Cost of 20 cal.=$120

Cost of 1 cal.=120/20

So,

cost of 5 calculators=

120/20*5

=$30

Hope it helps you

What is the distance of -a and a?

Answers

Step-by-step explanation:

Distance = positive value

a + a = 2a

Answer:

I think its 0

Step-by-step explanation:

becuase if you add the same number but on is negative and the other is positve it is always a 0.

Example:

10 + (-10) = 0

Twenty-five less than the product of three and ten and five tenths.

Answers

Answer:

On the left side is "13", that is the whole number part. There are two digits on the right side, the 7 is in the "tenths" position, and the 6 is the "hundredths" position. So, 13.76 is "13 and 7 tenths and 6 hundredths".

Step-by-step explanation:

Answer:

3 x 10 x .5 - 25

Step-by-step explanation:

Is your expression

Find the surface area of the following prism:
6 m
6 m
10 m
7.2 m
4.8 m

Answers

Answer:

172.8m³

Step-by-step explanation:

1/2(7.2)(4.8)(10)=172.8m³

For which Inequality would x= 4.5 not be a solution?
12-28
O8x+5>0
9x-5 <80
Ox+62 10

Answers

Answer:

12-28

Step-by-step explanation:

Please help I think it’s 4.0cm2 I’m i right?

Answers

Answer:

yes u are right give me brainlest plzzzzzzzzzzzzzzzzzzzzzzzzzz

Step-by-step explanation:

1 1/18 + 3 1/18 + 1 2/9 + 1 2/9

Answers

Answer:

6.55555555556

Step-by-step explanation:

Answer:

6 10/18 i think

Simplified is 6 5/9

improper fraction is 118/18

Step-by-step explanation:

What is the solution of log2x + 6 8 = 3?

Answers

Answer:

x=-3

Step-by-step explanation:

log(2x + 6) +8 = 3

Solve this log equation for x

First subtract 8 from both sides

log(2x+6)= -5

Now we convert it into exponential form

If log(x) = a then 10^a = x

log(2x+6)= -5 becomes

subtract 6 from both sides

Now we divide by 2 on both sides

x= -3 approximately

If the slope between the points (-5,7) and (4,x) is 1, then
what is the value of x?

Answers

9514 1404 393

Answer:

  16

Step-by-step explanation:

The equation of a line with slope m=1 through the point (h, k) = (-5, 7) will be ...

  y -k = m(x -h)

  y -7 = x +5

  y = x +12

Then for x = 4, the value of y is ...

  y = 4 +12 = 16

The point is (4, x) = (4, 16), so x = 16.

Answer:

16

Step-by-step explanation:

Given that the slope of the line is 1 . And it passes through the points (-5,7) and (4,x) .We know that slope is difference of ordinate by difference of abssica . So that ,

[tex]\implies Slope =\dfrac{y_2-y_1}{x_2-x_1}\\\\\implies 1 =\dfrac{ 7-x}{-5-4} \\\\\implies 1 \times -9 = 7-x \\\\\implies -9 -7 = -x \\\\\implies \underline{\underline{ x = 16 }}[/tex]

Hence the required answer is 16 .

Claim: Is Juan correct ??


Evidence : Show you work


This is geometryyyy(similarity)

Can you help me plz

Answers

He is correct
15/5 = 18/6 is true,
they are also the same shape, just a smaller version? I have no idea how to phrase it but the triangles are similar
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