Jeff and Kirk can build a​ 75-ft retaining wall together in 4 hours. Because Jeff has more​ experience, he could build the wall by himself 1 hour quicker than Kirk. How long would it take Kirk​ (to the nearest​ minute) to build the wall by​ himself?

Answers

Answer 1

Answer:

  8 hours 32 minutes

Step-by-step explanation:

Working together, the construction rates add. We can use the given relation to write an equation for the total time when the pair work together.

__

setup

Let k represent Kirk's time (in hours) to build the wall by himself. Then (k-1) is the time it takes for Jeff to build it. Their working-together rate in "walls per hour" is ...

  1/k +1/(k -1) = 1/4

__

solution

Multiplying by 4k(k-1), we have ...

  4(k-1) +4k = k(k -1)

  k² -9k = -4 . . . . . . . . subtract 8k and simplify

  k² -9k +20.25 = 16.25 . . . . . add (9/2)² to complete the square

  k -4.5 = √16.25 . . . . . . . . . take the square root

  k = 4.5 +√16.25 ≈ 8.531129 . . . hours

The fractional hour is ...

  0.531129 × 60 min ≈ 31.9 min ≈ 32 min

It would take Kirk about 8 hours 32 minutes to build the wall by himself.

_____

Additional comment

For most "working together" problems the rates of completing work need to be expressed in jobs per unit time. Usually, the rates are given in terms of time per job, as they are here. That is why reciprocals get involved.

Answer 2

It will take Kirk about 8 hours 32 minutes to build the wall by himself.

What is Quadratic Polynomial?

Quadratic equations are second-degree algebraic expressions and are of the form ax² + bx + c = 0.

Here, Let k represent Kirk's time (in hours) to build the wall by himself. Then (k-1) is the time it takes for Jeff to build it. Their working-together rate in "walls per hour" is ...

 1/k +1/(k -1) = 1/4

Multiplying by 4k(k-1), we have ...

 4(k-1) +4k = k(k -1)

 k² -9k = -4 . . . . . . . . subtract 8k and simplify

 k² -9k +20.25 = 16.25 . . . . . add (9/2)² to complete the square

 k -4.5 = √16.25 . . . . . . . . . take the square root

 k = 4.5 +√16.25 ≈ 8.531129 . . . hours

The fractional hour is ...

 0.531129 × 60 min ≈ 31.9 min ≈ 32 min

Thus, It will take Kirk about 8 hours 32 minutes to build the wall by himself.

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Related Questions

Share £20 in the ratio 2:3

Answers

Answer:

£8 : £12

Step-by-step explanation:

2:3 means that there are 5 parts in total. Let parts be represented as p. 5p = £20, p = £4. That meant 2 parts = £8 and 3 parts = £12. Hence to share £20 in the ratio 2:3 is £8 : £12

A jug of drinking water contained 1 2/3 gallons. If 5/7 gallon is drinked each day, how much water was left in the jug after 2 days?

Answers

Answer:

The answer is 5/21 water left in the jug after 2 days.

Step-by-step explanation:

First convert 1 2/3 into a improper fraction. This will turn it into 5/3. After this, find a common denominator between 5/7 and 5/3. This common denominator is 21. Now, convert both fractions into a fraction with 21 as the denominator. This will transform 5/7 into 15/21, and 5/3 into 35/21. So we know from the equation that 15/21 is drank every day. So we multiply 15/21 by 2, which will make it 30/21. 35/21 will stay the same. Now we do 35/21 - 30/21, which gives you the final answer of 5/21 water left in the jug after 2 days.

Hope this helps!

Write and simplify the equation you would use to solve the problem below.

A farmer builds a rectangular pen with a perimeter of 116 feet. If the length is 5 feet more than the width, what is the width?
A.w + 5 = 116
B.4w + 10 = 116
C.2w + 5 = 116
D.2w + 10 = 116

need a hand i cant figure this one out

Answers

Answer:

4w + 10 = 116

Step-by-step explanation:

Call the width w.

The length is 5 more than that, so the length is w + 5

Perimeter is 2w + 2l

2w + 2(w+5) = 116

Distribute the 2 to the values in the parentheses.

2w + 2w + 10 = 116

Combine like terms

4w + 10 = 116

Which statement describes the end behavior of the function f(x)= |x-7| -7?

A. As x approaches negative infinity, f(x) approaches negative infinity.
B. As x approaches negative infinity, f(x) approaches positive infinity.
C. As x approaches positive infinity, f(x) is no longer continuous.
D. As x approaches positive infinity, f(x) approaches negative infinity.

Answers

Answer:

A. B. C. D.

Step-by-step explanation:

because Which statement describes the end behavior of the function f(x)= |x-7| -7?

A. As x approaches negative infinity, f(x) approaches negative infinity.

B. As x approaches negative infinity, f(x) approaches positive infinity.

C. As x approaches positive infinity, f(x) is no longer continuous.

D. As x approaches positive infinity, f(x) approaches negative infinity.

What is the slope of the line that passes through the points (-7, -2)(−7,−2) and (-15, -14)(−15,−14)? Write your answer in simplest form.

Answers

Answer:

please help me find em ah and I will be able to do what I can

A group of students at Brunel university took a test in marketing and they needed to score 50 to pass. The results showed that the final grades have a mean of 62 and a standard deviation of 8. Suppose we approximate the distribution of these grades by normal distribution. Based on this information, you are required to perform the following; a) what percetage(to 3 decimals) of the students scored more than 78? B) what percentage of the students to 3 decimal places scored under 50? And c) what percentage to 3 decimal places of the students scored between 60 and 80?

Answers

Answer:

My answer: 15.87%

Step-by-step explanation:

The Final grades follows normal distribution.

It means =70

The Given standard deviation =10

The normal random variable of a standard normal distribution is called a standard score or a z-score. In Every normal condition, random variable X will be transformed into a z score via the following equation:

z=(X)

But when X is a normal random variable, μ is the mean of X.

For That, it is X=60

Z=(60−70)/10=−1

P(X<60)=P(Z<−1)

=0.1587

Hence percent of students failed in test is 15.87%

Y-6.37x=-3 which of the following function notation corresponds to the equation below

Answers

Wheres the other part of the question

Helppppp meeeee pleaseeee?

Answers

Answer:

D

Step-by-step explanation:

A. The domain is not all real numbers since the domain of the inverse is the range of the square root function which is not all real numbers.

B and C. The domain is not x >= -4, that's the range since the domain and range are swapped relative to the original square root function which had a domain x >= 4 and a range x >= 0

D. This is true since the range of the square root function is x >= 0 which is now the range of the inverse.

A water sprinkler sends water out in a circular pattern. How large is the watered area if the radius of the watering pattern is 3 feet?

Use 3.14 for pi.

Answers

Answer:

28.26 feet squared

Explanation:

Area of circle is determined by : π(radius)²

Here given:

π = 3.14radius = 3 feet

Solve for area:

π(radius)²3.14(3)²28.26 feet²

Answer:

28.26 feet squared

Step-by-step explanation:

Radius of the watering pattern = 3 feet

Area = π r²

= 3.14 × 3²

= 28.26 feet squared

Use the Polygon tool to draw an image of the given polygon under a dilation with a scale factor of 14 and center of dilation ​(0, 0)​.

Answers

The points are (168, 168) , (168,56) , (112,0) , (70,112)

Given a scale factor is 14 and the center of dilation (0,0)

We need to find the Points using the scale factor and polygon tool

Now to find the new points the equation is

(old points - dilation center)*scale factor + dilation center

As we know the origin is the dilation center which simplifies to

(old point)*dilation center

(12,12) * 14  =  (168,168)

(12,4) * 14 = (168, 56)

(8,0)*14  =   (112, 0)

(5,8) *14  = (70, 112)

Hence the new points are  (168, 168) , (168,56) , (112,0) , (70,112)

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A football team has attempted 6 running plays. The change in field position resulting from each play is shown in the table. Running Play Outcomes Play 1 –3 yards Play 2 2 yards Play 3 –1 yard Play 4 –2 yards Play 5 –3 yards Play 6 1 yard What is the average change in field position per running play? –6 yards per play –1 yard per play 0 yards per play 1 yard per play Mark this and return

Answers

Answer:

Step-by-step explanation:

-3 +2 +-1 +-2 +-3 +1 = -6 yards total

-6 / 6 =  -1 yard per play average

In the past month, Ryan has had five pizzas delivered. He kept a record of how long it took to get the
pizzas: 35 minutes, 25 minutes, 15 minutes, 40 minutes, and 50 minutes.
If the sixth time he orders pizza, it takes 95 minutes, how will this affect his data?
a.) It will have little to no effect on both the mean and the median.
b.) It will have little to no effect on the mean, but it will make the median a less useful measure
of center.
c.) It will make both the mean and the median less useful measures of center.
d.) It will have little to no effect on the median, but it will make the mean a less useful measure
of center.

Answers

It will have little to no effect on the median, but it will make the mean a less useful measure of center.

How to determine the effect?

The initial data elements are given as:

35, 25, 15, 40, 50

When a new data element is added, we have:

35, 25, 15, 40, 50, 95

See that 95 is far from the other data elements.

This means that 95 is an outlier of the data elements

Outliers have effects on the mean and it renders the mean useless.

However, it has little to no effect on the median

Hence, the true statement is (d)

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Answer:

Step-by-step explanation:

it will have little to no effect on the median but will make the mean a less useful measure of center.

What is the exact value of sin (- 105)?​

Answers

Answer:

Just put it into a calculator

0.97053528353

[tex]\text{Let's find the sine of -105 degrees}\\\text{Start by typing -105 into our calculator}\\\text{and click the sin button}\\\text{It gives us an irrational number, which is the sine of -105 degrees}[/tex]

[tex]\rule{300}{1.7}[/tex]

[tex]\text{The value is end less, it would take an eternity to type it here,}\\\text{ but I will round it to the nearest 100th}[/tex]

[tex]\rule{300}{1.7}[/tex]

[tex]\text{-0.97}[/tex]

Charlotte practices the piano for 4 hours each week. How many minutes does she practice each week?

Answers

charlotte practices 240 minutes per week

Answer:

4 X 60 = 240 minutes

Step-by-step explanation:

there are 60 minutes in each hour

Translate this sentence into an equation. Craig's savings decreased by 23 is .55

Answers

Answer:

x-23=.55

Step-by-step explanation:

Answer: 0.55 = x - 23

Step-by-step explanation:

let his savings = x

By selling a table for sh.56, gain is as much as percent as its cost in dollars. What is the cost price? By selling a table for sh.56 , gain is as much as percent as its cost in dollars . What is the cost price ?​

Answers

The cost price of the table is $40.

What is Gain ?

Gain is the amount gain by selling the product at a higher price than its cost.

Let the cost of the table is $ x

The percentage gain is x%  (as given in the question)

Cost price = ?

It is known that

Step 1 : Gain = ( selling Price - Cost Price) * 100 / Cost Price

Selling price = 56

Cost Price = $ x

Therefore substituting the value

x = (56 - x) * 100 / x

x² = 5600 - 100x

x² +100x -5600 = 0

Step 2 : Factorizing

x² + 140x - 40 x -5600 = 0

x( x+14 ) -40( x +14) = 0

( x - 40)(x +14) = 0

x = $40

Therefore the cost price of the table is $40.

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Please assist with the following questions​

Answers

The answers for following questions are;

i. $244.64

ii. $ 5314.64

What is future value?

Future value (FV) is the value of a current asset at a future date based on an assumed rate of growth. The future value is important to investors and financial planners, as they use it to estimate how much an investment made today will be worth in the future.

Here, future value or amount;

          A = P(1 + r)ⁿ

Where,

A = future value = ?

P = principal = $ 12,300

r = interest rate = 6%/12 = 0.06/12 = 0.005

n = number of periods = 12 X 6 years = 72

A = P(1 + r)ⁿ

= 12,300(1 + 0.06/12)⁷²

= 12300 (1 + 0.005)⁷²

= 12300 (1.005)⁷²

= 12300 (1.4384)

= 17,614.64

Each monthly payment = Total payment / number of months

= $17,614.64 / 72

= $ 244.64

Total amount of interest = Total payment - Principal payment

                                          =   17,614.64 - 12300

                                          =   $ 5314.64

Thus, The answers for following questions are;

i. $244.64

ii. $ 5314.64

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What is the mean for 14,14,14,15,15,15,15,15,16,16,16,16,17,17,17,17,17,17,17,17,17,17,18,18,18,18,18,18,18,19,19,19,19,20,20,20,20,20,21,21,21,21,22,22,22,23,23,23,23,23,24,24,24,24,24,24,25,25,25,25

Answers

Answer:

Mean: 19.366666666667

Step-by-step explanation:

Mean: Average of the Data set

If you add the numbers below and divide them by the amount of numbers there are, you will get the average of the data set.

14,14,14,15,15,15,15,15,16,16,16,16,17,17,17,17,17,17,17,17,17,17,18,18,18,18,18,18,18,19,19,19,19,20,20,20,20,20,21,21,21,21,22,22,22,23,23,23,23,23,24,24,24,24,24,24,25,25,25,25

Average= sum/count

Mean= 1162 / 60

Mean= 19.366666666667

Rounded to the nearest tenth: 19.4

Rounded to the nearest hundredth: 19.37

This whole page i need help on

Answers

Step-by-step explanation:

1. True

2. False

3. True

5. Falsw

6.True

7.True

8.False

10.True

15. always

17. always

world problem in length (trigonometry) geometry not chemistry

Answers

Answer:

≈ 47.2 m

Step-by-step explanation:

let the height from the sea to the base of lighthouse be h₁

let the height from the sea to the top of the lighthouse be h₂

using the tangent ratio in the right triangle

tan55.1° = [tex]\frac{opposite}{adjacent}[/tex] = [tex]\frac{h_{1} }{610}[/tex] ( multiply both sides by 610 )

h₁ = 610 tan55.1°

tan56.5° = [tex]\frac{h_{2} }{610}[/tex] ( multiply both sides by 610 )

h₂ = 610 tan56.5°

then

height of lighthouse = h₂ - h₁        

                                  = 610 tan56.5° - 610 tan55.1°

                                  = 610(tan56.5° - tan55.1° )

                                 ≈ 47.2 m ( to the nearest tenth )

《QUESTION 1》
The length of the side of a square is 50 cm and the breadth of a rectangle is 25 cm. If the areas of the square and the rectangle are equal, find the length of the rectangle.

《QUESTION 2》
A wire is in the shape of a rectangle with length 6 cm. It is bent to form a square whose side is 5 cm. Find the breadth of the rectangle. Also, calculate the areas of both the rectangle and the square and find which shape encloses more areas.​

Answers

The length of the rectangle is 100cm.

The breadth of the rectangle is 4cm.

The square encloses more area than the rectangle.

What is the length of the rectangle?

The first step is to determine the area of the square.

Area of a square = length² = 50² = 2500 cm²

Area of a rectangle = length x width

length = area / width

2500 / 25 = 100cm

What is the breadth of the rectangle?

The first step is to determine the perimeter of the square.

Perimeter = 4 x length

4 x 5 = 20cm

Perimeter of a rectangle = 2(length + width)

breadth = (perimeter / 2) - length

(20 / 2) - 6

10 - 6 = 4cm

Area of the square = 5 x 5 = 25

Area of the rectangle = 6 x 4 = 24

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What is the median of these figure skating ratings?
5.0 6.0 7.0 7.5 8.0 9.0 10.0

Answers

Answer:

5.0 6.0 7.0 7.5 8.0 9.0 10.0

arranging the following

5.0 , 6.0 , 7.0 , 7.5 , 8.0 , 9.0, 10.0

7.5 is the median..

Which statement is correct when a scatterplot is constructed?
The independent variable is the input variable and should be represented by the x-axis.
The independent variable is the input variable and should be represented by the y-axis.
The dependent variable is the input variable and should be represented by the x-axis.
The dependent variable is the input variable and should be represented by the y-axis.

Answers

Option A is the correct answer.

The independent variable is the input variable and should be represented by the x-axis.

What is Variable?

A variable is a symbol and placeholder for a quantity that may change, or any mathematical object. In particular, a variable may represent a number, a vector, a matrix, a function, the argument of a function, a set, or an element of a set.

For the Scatterplot, out of given options,

Option A is the correct option which represents The independent variable is the input variable and should be represented by the x-axis.

Thus, The independent variable is the input variable and should be represented by the x-axis.

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Packs of stickers
Buy for €1.50a pack
Sell For £2.25 a pack
Media buys 5 pack's and sells them all
How Much profit does she
Make ?

Answers

Answer:

€3.75

Step-by-step explanation:

1. Formulate:

5×(2.25 - 1.5)

2. Calculate:

5×(2.25-1.5)

5× 0.75

=3.75

Answer

3.7/ €3.7

Sum of 1/2*3 +1/3*4 +1/4*5 ..1/99*100

Answers

Answer:

11∗2+13∗4+15∗6+⋯+199∗100=?

=(1−12)+(13−14)+(15−16)+⋯+(199−1100)

=(1+13+15+17+⋯+199)−(12+14+16+⋯+1100)

=(1+13+15+17+⋯+199)−12(1+12+13+⋯+150)

=∑k=15012k−1−∑k=15012k

Continue further.

The intensity of a radio signal from the radio station varies inversely as the square of the distance from the station. suppose intensity is 8000 units at a distance of 2 miles. what will the intensity be at a distance of 11 miles? round your answer to the nearest unit.


The answer is B. 222 Units

Answers

The answer is b 222 units

These tables of values represent continuous functions. For which function
will the y-values be the greatest for very large values of x?
y
1 7
2 21
3 63
4 189
5 567
B. x
y
17
2 207
3 407
4 607
5 807
C.xy
1 325
2 400
3 475
4 550
5625
Y
1 565
2 570
3 575
4 580
5585
What is the answer??

Answers

Answer: the answer is a

Step-by-step explanation:

what is the average daily balance for the February 1-28 billing period in the table?​

Answers

i think it’s 311.75?
i added the closing balances and divided by the 4 selected days

either that or 44.54 if you divide by 28 days of February instead…

i might be wrong though

El perímetro de un rectángulo es de 72 cm. Halla el área del rectángulo si su largo es el 25% más grande que su ancho

Answers

Answer:

Las dimensiones del rectángulo son:

ancho = 16 cm

largo = 20 cm

Step-by-step explanation:

Consideración:

La formula del perímetro de un rectángulo es:

perímetro = 2(largo + ancho)

25% más grande = 125% = 125/100 = 1.25

Planteamiento:

2(a+b) = 72

b = 1.25a

a = longitud del ancho

b = longitud del largo

Desarrollo:

de la primer ecuación del planteamiento:

a+b = 72/2

a+b = 36

b = 36 - a        Ec. 3

Igualando la segunda ecuación del planteamiento con la Ec. 3:

1.25a = 36 - a

1.25a + a = 36

2.25 a = 36

a = 36/2.25

a = 16

de la Ec. 3:

b = 36 - a

b = 36 - 16

b = 20

Comprobación:

de la primera ecuación del planteamiento:

2(a+b) = 72

2(16+20) = 72

2*36 = 72

What is the answer to the question

Answers

Answer:

180 cm squared

Step-by-step explanation:

Area Of A Rectangle is Length times Width, so 20 times 9, which equals 180.

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