Rayna is building a tapered staircase using wooden boards. The bottom stair is 3 1/2 ft wide, and the top stair is 2 1/6 ft wide. Each stair is 4 in. Shorter than the one below. What is the total length of wooden boards rayna needs for the stair tops, in feet? Enter your answer as an improper fraction.

Answers

Answer 1

   Sum of an arithmetic sequence is defined by the formula,

[tex]T_n=\frac{n}{2}[2a+(n-1)d][/tex]

Total length of the wooden boards will be [tex]14\frac{1}{6}[/tex] feet.

    It's given in the question,

Width of the bottom stair = [tex]3\frac{1}{2}[/tex] feetWidth of the top stair = [tex]2\frac{1}{6}[/tex] feetEach stair is 4 inch shorter than the one below.

Since, 1 inch = [tex]\frac{1}{12}[/tex] feet

Therefore, [tex]4[/tex] inch = [tex]\frac{4}{12}[/tex] feet

                             = [tex]\frac{1}{3}[/tex] feet

So, each stair is [tex]\frac{1}{3}[/tex] feet shorter than one below.

Now the sequence formed will be,

[tex]\frac{7}{2},[\frac{7}{2}-\frac{1}{3}],[\frac{7}{2}-\frac{2}{3}],......\frac{13}{6}[/tex]

[tex]\frac{21}{6},\frac{19}{6},\frac{17}{6}....\frac{13}{6}[/tex]

It's an Arithmetic sequence with common difference 'd' = [tex]-\frac{1}{3}[/tex] and first term 'a' = [tex]\frac{7}{2}[/tex] and nth term [tex]T_n=\frac{13}{6}[/tex]

If there are 'n' stairs, expression for the for the top stair of the arithmetic sequence will be,

[tex]T_n=a+(n-1)d[/tex]

[tex]\frac{13}{6}=\frac{21}{6}+(n-1)(-\frac{1}{3})[/tex]

[tex]\frac{13}{6}-\frac{21}{6}=-(n-1)\frac{1}{3}[/tex]

[tex]\frac{8}{6}=(n-1)\frac{1}{3}[/tex]

[tex]\frac{4}{3}=(n-1)\frac{1}{3}[/tex]

[tex](n-1)=4[/tex]

[tex]n=5[/tex]

Therefore, there are 5 stairs.

Now total length of the wooden boards = Sum of 5 terms of the sequence

                                                                    = [tex]\frac{n}{2}[2a+(n-1)(d)][/tex]

                                                                    = [tex]\frac{5}{2}[2(\frac{21}{6})+(5-1)(-\frac{1}{3})][/tex]

                                                                    = [tex]\frac{5}{2}[\frac{21}{3}-\frac{4}{3}][/tex]

                                                                    = [tex]\frac{17}{3}\times \frac{5}{2}[/tex]

                                                                    = [tex]\frac{85}{6}[/tex]

                                                                    = [tex]14\frac{1}{6}[/tex] ft

    Therefore, total length of the wooden boards will be [tex]14\frac{1}{6}[/tex] ft.

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Related Questions

Los vértices de un triángulo en el plano cartesiano son A(-3, 4), B(4, 4) y C(4, -3). ¿Cuál es el área en unidades cuadradas del triángulo?
rapido pllsssss​

Answers

El área del triángulo es de 24.5 unidades cuadradas.

En este problema, procedemos a resumir el procedimiento como sigue:

1) Calculamos las longitudes de los segmentos de línea AB, BC y AC por medio de la ecuación de longitud del segmento de línea.

2) Determinamos el semiperímetro del triángulo.

3) Determinamos el área del triángulo mediante la fórmula de Herón.

Si tenemos que [tex]A(x,y) = (-3, 4)[/tex], [tex]B(x,y) = (4, 4)[/tex] and [tex]C(x,y) = (4, - 3)[/tex], entonces aplicamos el procedimiento como sigue:

Paso 1 - Longitudes de segmentos línea

Segmento AB

[tex]l_{AB} = \sqrt{[4-(-3)]^{2}+(4-4)^{2}}[/tex]

[tex]l_{AB} = 7[/tex]

Segmento BC

[tex]l_{BC} = \sqrt{(4-4)^{2}+[(-3)-4]^{2}}[/tex]

[tex]l_{BC} = 7[/tex]

Segmento AC

[tex]l_{AC} = \sqrt{[4-(-3)]^{2}+(-3-4)^{2}}[/tex]

[tex]l_{AC} = 7\sqrt{2}[/tex]

Paso 2 - Cálculo del semiparámetro

[tex]s = \frac{l_{AB}+l_{BC}+l_{AC}}{2}[/tex]

[tex]s = \frac{14+7\sqrt{2}}{2}[/tex]

[tex]s = 7 + \frac{7\sqrt{2}}{2}[/tex]

Paso 3 - Cálculo del área del triángulo

[tex]A = \sqrt{s\cdot (s-l_{AB})\cdot (s-l_{BC})\cdot (s-l_{AC})}[/tex]

[tex]A = 24.5[/tex]

El área del triángulo es de 24.5 unidades cuadradas.

Invitamos cordialmente a ver esta pregunta sobre áreas de triángulos: https://brainly.com/question/21677292

Help!! (Edgar's midterm have two screenshot's)

Answers

Answer:

Step-by-step explanation:

2)

80 +67 +97+ 98 +85 +72 = 499

499/6=83.1666666667

Average: 83.1666666667

3)

a) 97 93 92 90 90 90 86 =90

median of Edgars grades for his midterm is 90

99 93 93 89 88 88 86

median of Edgars grades for his trimester is 89

7)

(z+9+18)= z+27 (remember don't mix the numbers if they are attached to the x)

(z+18+9)= z+27 (because adding is both ways the same)

a) a + b =b + a

Geometry

1.

a) 6x^2

b)The surface area of a cube = 6a^2 where a is the length of the side of each edge of the cube. Put another way, since all sides of a cube are equal, x is just the length of one side of a cube

c) The unit would be sq(squared) feet

I need help please. It’s due tomorrow! I’m confused

Answers

Let’s solve Quadrant by Quadrant , and please ignore the NEGATIVE Coordinates; Take all distance values to be POSITIVE

Scenario also requires Pythogras theorem & knowing properties of triangles


Triangle One[1] :

Base or Horizontal line [ A] =4 squares & Height or Vertical line [ B] =7 Squares. Those are easily obtained by counting . Remaining bit , the Slant is the Hypotenuse, let’s Lebel it C

In Pythogras for a right angled triangle,

A^2+B^2=C^2

substitute

4^ 2 +7^2=C^2

16 + 49 = C^2

65 =C2

√ 65 = 8.0622 Units

hence A[ Base ] =4 units , B [ Height] =7 units , C[ Hypotunese] =8.062 units


Triangle 2 :

Base [ Horizontal, A ] = 5 Units , Height [. reticle ] =7 Units , Hypotunese [ C] =?

A^2 + B ^2 =C^2

5^2+ 7^2 =C^2

25 + 49 = C^2

74 =C^2

√74 = 8.602 Units

There fore A = 5 units , B=7 units & C= 8.602 units


Triangle 3

Base[ A] =8 Units , Height [ B] = 2 units , Hypotunese C =? units

8^2 + 2^2=C^2

64 + 4 = C^2

68 =C^2

√68 =C =8.25Units

Triangle 4

Devide the base into two equal parts to get 2 Units each , Height is 2

Upon doing that , that , you get two equal small triangles with the Same Lengths Hypotenuse

Let’s only solve off the Hypotunese one small triangle

Base [ A]=2, Height =2, Hypotunese [ C] =?

Using A^2 + B ^2=C^2

2^2 +2^2=C^2

8 =C2

√8 =2.83 Units







How would you classify the number -3 (NEGATIVE three) *
Natural Number, Whole Numer, Integer, Rational Number
Whole Number, Integer, Rational Number ONLY
Integer, Rational Number ONLY
Rational Number ONLY

Answers

-3 is an integer and rational number

Factoring trinomials: m^2 +13m-36

Answers

Answer:

[tex]m^2 +13m-36[/tex] does not factor.

Explanation:

[tex]m^2 +13m-36[/tex] is not factorable with rational numbers.

326-184=? umm sorry for asking but have homework and needs to be done by 9:30

Answers

Answer:

142 is the answer of this your homework

simplify this exponential expression

[tex]( \frac{1}{3} )^{2} [/tex]​

Answers

Answer:

Answer: 3^-2

Step-by-step explanation:

[tex]( \frac{1}{3} ) {}^{2} \\ \\ = \frac{ {1}^{2} }{ {3}^{2} } \\ \\ = {3}^{ - 2} [/tex]

Answer:

[tex]\frac{1}{9}[/tex]

Step-by-step explanation:

Evaluate the power

[tex]\frac{1^2}{3^2}[/tex]

Divide

[tex]\frac{1}{9}[/tex]

The equation R=30A-50 represents the revenue R (in dollars) you make by spending A dollars on advertising. Your revenue totaled $160. How much did you spend on advertising?

Answers

Answer: $7

Step-by-step explanation:

R = Revenue = $160

$160 = 30A - 50

(+50) (+50)

210 = 30A

(÷30) (÷30)

$7 = A

13. Very hard for me

Answers

Answer:

A

Step-by-step explanation:

help me plz, 13 points! these questions are separate. help me work out both questions please ​

Answers

2x+20 makes more sense to the math question

2x-7>3
Two step inequalities

Answers

2x-7>3
2x>10
x>5
The answer is x>5

I need the steps and answers please

Answers

Step-by-step explanation:

[tex]3(2x - 5) = 6(x + 3)[/tex]

[tex]6x - 15 = 6(x + 3)[/tex]

[tex]6x - 15 = 6x + 18[/tex]

[tex] - 15 = 18[/tex]

[tex] = x∈\O[/tex]

what does x=
please explain!

Answers

Answer:

x=37°

Step-by-step explanation:

2x°=74° (vertically opposite angles)

2x°/2=74°/2

x=37°

74° = 2x°

2x° = 74°

x° = 74° : 2

x° = 37°

find the equation of a line whose gradient is -¾ and y intercept is 2​

Answers

Answer:y =-3x/4+2

Step-by-step explanation:

Slope= -3/4

The line is passing through (0,2).

y-2=(x-0)*-3/4

or

y =-3x/4+2

Wilbur Wright was born in 1867 his brother Orville was born in 1871 how old was each brother in 1903

Answers

Answer:

Wilbur Wright was 36 and his brother Orville was 32 in 1903

How to find the rate of change

Answers

Step-by-step explanation:

Rate of change = Slope

for Q11)

we take 2 points to find the slope P1 (0,-3)

P2 (1,1)

[tex]slope = \frac{(y2 - y1)}{(x2 - x1)} [/tex]

= (1 - (-3))/(1-0)

= 4

Q12

P1 (0,1)

p2 (1 , -2)

-3/1 = -3

Q13

p1 ,(25 ,65)

p2 (26, 68)

slope = 3

ignore the computer lineslol

Answers

Answer:

2 acute and 1 right

Step-by-step explanation:

because in a right triangle theres two acute angle and 1 right

The sales of Horizon, a cell phone sales and service provider, were $127,693,100 last year. What is the value of the 6th digit in this number?

Answers

Answer:

600000

Step-by-step explanation:

Cuz it is in the 100000 spot

Answer:

600000

Step-by-step explanation:

Based on the place value system, the digits are ordered from the right to left. So the 6th digit is 6 located in the hundreds of thousands column. The value of the 6th digit is obtained by multiplying the digit by the value of it's place value column

i.e 6 * 100,000 = 600, 000

Ans: 600,000

1. a. In an examination, 60 candidates sat for either Mathematics or English language 20% passed in Mathematics only and 40% passed in English language only. If each candidate passed in at least one of the subjects, how many candidates passed in i. Mathematics ii. English language? b. Illustrate the information given in (a) on a Venn diagram c. Daddy had GH¢50.00 in his pocket. He gave half of the amount to Mama; he also gave GH€10 to the house boy later. What fraction of the amount was left on him? 2. a. i. Find the width of a cuboid with height 8m and length 12m, given that the volume is 480m ii. Calculate the total surface area of the cuboid b. Find the truth set of: 1 - m + m -3 = 6 5 4​

Answers

The number of students who Passed mathematics is 36 and the number who passed English is 48

The fraction of the amount left to Daddy is 3/10

The width of the cuboid is 5 meter and it's surface area is 380 meter

A.)

Total Number of students = 60

Since each candidate passed in atleast one of English and Math ; the none of the students failed.

Percentage who passed :.

Mathematics only = 20%

English only = 40%

Since, no one failed ; percentage that passed both = 100% - (40+20)% = 40%

Number who passed Mathematics only :

20% × 60 = 12 students

Number that passed English only :

40% × 60 = 24 students.

Number that passed both = (40% × 60) = 24 students

Number that passed English = (Number that passed English only + Number that passed both) = 24 + 24 = 48

.Number that passed mathematics = (Number that passed Maths only + Number that passed both) = 12 + 24 = 36

2.)

Total daddy has = 50

Half given to mummy = 1/2 × 50 = 25

Amount given to houseboy = 10

Amount left = 50 - (25 + 10) = 15

Fraction of Amount left = 15/50 = 3/10

C.)

Length of cuboid = 12

Height = 8 cm

Volume of cuboid = 480

Width = w

Recall :

Volume = Length × width × height

480 = 12 × 8  × w

480 = 96w

w = 490 / 96

w = 5

Width of the cuboid = 5

The surface area of a cuboid : 2(lh + lw + hw)

Hence,

2([(12×8) + (12×5) + (8 ×5)]

2(96 + 60 + 40)

2(190)

380 m

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https://brainly.com/question/18112348

Find the ratio of triangles to circles in the diagram below

Answers

Answer:

Ratio should be equal so ratio is 3:3

PLEASE MARK ME BRAINLIEST.

The ratio of the triangles to circles in the diagram below would be; 1: 1

What is the ratio of two quantities?

Suppose that we've got two quantities with measurements as 'a' and 'b'

Then, their ratio(ratio of a to b) a:b We usually cancel out the common factors from both the numerator and the denominator of the fraction we obtained.

Thus, there are three circles and three triangles shown in the figure.

Therefore, the ratio will be;

three circles: three triangle

3 : 3

1: 1

Hence, the ratio of the triangles to circles in the diagram below would be; 1: 1

Learn more about ratios here:

brainly.com/question/186659

#SPJ2

Sketch the angle in standard position.
1. -450°

Answers

Answer:

When we draw the angle in what is known as standard position, we put its vertex at the origin, and we draw the initial side of the angle along the positive horizontal axis. ... The amount of that rotation corresponds to the measure of the angle.

Step-by-step explanation:

i think the answer _ 2/60

Please help but actually answer correctly
Find the complement of set B in-universe U.

U is the set of natural numbers less than or equal to 8
B is the set of even factors of 8

Answers

Answer:

B' = {1, 3, 5, 6, 7}

Step-by-step explanation:

U = {1, 2, 3, 4, 5, 6, 7, 8}

B = {2, 4, 8}

So the complement  ( the set of elements in U but not in B) is:

B' = {1, 3, 5,  6, 7}

Jennifer is saving money to buy a bike. The bike costs $261. She has $107 saved, and each week she adds $14 to her savings.

How long will it take her to save enough money to buy the bike?

It will take her ____ weeks to save for the bike.

Answers

Answer:

It will take her 11 weeks to save for the bike

Step-by-step explanation:

261 -107 = 154

154 /14=11

In which of the following expressions is the coefficient of term "x" 1?

2x^2+x−9

3x^2−x−5

2x^2−3x+1

x^2+2x+7

Answers

Answer:

the answer of the following question is d

You are walking directly away from your house. You are 5 miles away from your house when you start walking, so you can determine your distance from your house by adding 5 to the number of miles you have walked. In the equation below, x represents the number of miles you have walked, and y represents your distance from home in miles.

The relationship between these two variables can be expressed by the following equation:
y=x+5

Identify the dependent and independent variables.

Answers

Answer:

y is the dependent variable and x is the independent variable

Step-by-step explanation

The number on the right of the equal sign is always the independent variable and the number on the left is always the dependent variable.

independent variable = dependent variable +5

14 less than f
what is it?

Answers

f-14 because 14 less than a number means to subtract 14 from that number.

the proceeds from a car wash are directly proportional to the number of cars washed. the total after 9 cars was $180.

a. how much can be raised if 60 cars are washed? __

b. if $1,500 was earned from the car wash, how many cars were washed? __

Answers

Answer:

a) 1200

b) 75

Step-by-step explanation:

21 feet
You are standing 21 feet from a tree. You have a 25-inch stick you are holding 35 inches from your eye. You see that the top of the tree
exactly matches the top of the stick you are holding. The bottom of the stick exactly matches the bottom of the tree. How tall is the tree?

Answers

Step-by-step explanation:

don't know man I don't know it

PLEASE HELP!! What is the standard deviation of a data set whose values are all the same?


A. −1


B. 0


C. 1


D. −2

Answers

Answer:

zero

Step-by-step explanation:

Answer:

I got this same question on my quiz, so I added the other two questions as well, with their answers.

Step-by-step explanation:

1. What is the standard deviation of the data set? Round to the nearest tenth if needed.

2, 4, 7, 8, 9

Answer: 2.9

2. Data Set A has a mean of 215 and a standard deviation of 35. Data Set B has a mean of 400 and a standard deviation of 12. Which data set is more spread out?

Answer: Data Set A

3. What is the standard deviation of a data set whose values are all the same?

Answer: 0

Help me please!
Solve the equation

Answers

Here,
Hope this may help you!
Please mark me as brainliest I really need it to upgrade my rank! And it is much appreciated.!
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