in how many ways can a class of 40 students select a committee from the class that consists of a president, a vice president, a treasurer and a secretary g

a. Hence proved that the sum of fractions  [tex]${\frac{1}{\sqrt{1+\sqrt{2}}}}+{\frac{1}{\sqrt{2+\sqrt{3}}}}+{\frac{1}{\sqrt{3}+\sqrt{4}}}=1$[/tex]

b. The value will be 7 for the expression

⇒ [tex]${\frac{ 1-\sqrt{2}}{-1}+{\frac{ \sqrt{2}-\sqrt{3}}{-1}+ \cdot \cdot \cdot+{\frac{\sqrt{63}-8}{-1}}$[/tex]

Square rοοt οf a number is a value, which οn multiplicatiοn by itself, gives the οriginal number. The square rοοt is an inverse methοd οf squaring a number. Hence, squares and square rοοts are related cοncepts.

Suppοse x is the square rοοt οf y, then it is represented as x=√y, οr we can express the same equatiοn as x² = y. Here, ‘√’ is the radical symbοl used tο represent the rοοt οf numbers. The pοsitive number, when multiplied by itself, represents the square οf the number. The square rοοt οf the square οf a pοsitive number gives the οriginal number.

Here,

a. [tex]${\frac{1}{\sqrt{1+\sqrt{2}}}}+{\frac{1}{\sqrt{2+\sqrt{3}}}}+{\frac{1}{\sqrt{3}+\sqrt{4}}}=1$[/tex]

Using (a + b)(a - b) = a² - b²

⇒ [tex]${\frac{1 \cdot \sqrt{1}-\sqrt{2}}{\sqrt{1}+\sqrt{2}\cdot \sqrt{1 }-\sqrt{2}}+{\frac{1 \cdot \sqrt{2}-\sqrt{3}}{\sqrt{2}+\sqrt{3}\cdot \sqrt{1}-\sqrt{2}}}+{\frac{1 \cdot \sqrt{3}-\sqrt{4}}{\sqrt{3}+\sqrt{4}\cdot \sqrt{3}-\sqrt{4}}}$[/tex]

⇒ [tex]${\frac{ \sqrt{1}-\sqrt{2}}{1-2}+{\frac{ \sqrt{2}-\sqrt{3}}{2-3}+{\frac{\sqrt{3}-\sqrt{4}}{3-4}}$[/tex]

⇒ [tex]${\frac{ \sqrt{1}-\sqrt{2}}{-1}+{\frac{ \sqrt{2}-\sqrt{3}}{-1}+{\frac{\sqrt{3}-\sqrt{4}}{-1}}$[/tex]

⇒ [tex]${\frac{ 1-\sqrt{2}}{-1}+{\frac{ \sqrt{2}-\sqrt{3}}{-1}+{\frac{\sqrt{3}-2}{-1}}$[/tex]

⇒ [tex]${\frac{ 1-\sqrt{2}}{-1}+{\frac{ \sqrt{2}-\sqrt{3}}{-1}+{\frac{\sqrt{3}-2}{-1}}$[/tex]

⇒ [tex]$ -1+\sqrt{2}}- \sqrt{2}+\sqrt{3}}-{\sqrt{3}+2}$[/tex]

⇒ [tex]$ -1+2}$[/tex]

⇒ 1

a. Hence proved that the sum of fractions  [tex]${\frac{1}{\sqrt{1+\sqrt{2}}}}+{\frac{1}{\sqrt{2+\sqrt{3}}}}+{\frac{1}{\sqrt{3}+\sqrt{4}}}=1$[/tex]

B. This will be done with the same process,

⇒ [tex]${\frac{ 1-\sqrt{2}}{-1}+{\frac{ \sqrt{2}-\sqrt{3}}{-1}+ \cdot \cdot \cdot+{\frac{\sqrt{63}-8}{-1}}$[/tex]

⇒ [tex]${\frac{ 1-\sqrt{2}}{-1}+{\frac{ \sqrt{2}-\sqrt{3}}{-1}+ \cdot \cdot \cdot+{\frac{\sqrt{63}-8}{-1}}$[/tex]

⇒ [tex]$ -1+\sqrt{2}}- \sqrt{2}+\sqrt{3}} \cdot \cdot \cdot -{\sqrt{63}+8}$[/tex]

There, will be same roots of every number until - 8

So,

⇒ [tex]$ -1+8}$[/tex]

= 7

b. The value will be 7 for the expression

⇒ [tex]${\frac{ 1-\sqrt{2}}{-1}+{\frac{ \sqrt{2}-\sqrt{3}}{-1}+ \cdot \cdot \cdot+{\frac{\sqrt{63}-8}{-1}}$[/tex]

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Answer:

54 sq in.

Step-by-step explanation:

For a cube, try using the rectangular prism formula. (there's an easier way but I prefer this one)

2lw + 2hw + 2lh

(2 × 3 × 3) + (2 × 3 × 3) + (2 × 3 × 3)

18 + 18 + 18 + 18

SA = 54 sq in

hope i explained it (you can search up the formula for a cube but i like this one)

Answer:

Let's call the cost of a blouse "b" (in dollars). Then, according to the problem, the cost of a dress is 3/4 of the cost of a blouse, or (3/4)b.

We know that Vicky paid $350 for 3 dresses and 4 blouses, so we can set up the equation:

3(3/4)b + 4b = 350

Simplifying this equation, we get:

9/4 b + 4b = 350

Combining like terms, we get:

17/4 b = 350

To solve for b, we can multiply both sides by 4/17:

b = 350 × 4/17 = $82.35 (rounded to two decimal places)

Therefore, the cost of a dress is:

(3/4)b = (3/4)($82.35) = $61.76 (rounded to two decimal places)

So each dress cost $61.76.

The calculation for the price of 10 books is as follows: 10 × (19.60/88) = 2.21

We can use a proportion to determine the cost of 10 books based on the cost of 88 books:

88 books cost $19.60

1 book costs 19.60/88 dollars

Now we can use this information to find the cost of 10 books:

10 books cost 10 × (19.60/88) dollars

Simplifying the expression on the right side, we get:

10 books cost $2.21

Therefore, the equation that would help determine the cost of 10 books is: 10 × (19.60/88) = 2.21 The cost of books is often calculated based on the number of books purchased and the price per book. In this problem, we are given the cost of 88 books, and we need to find the cost of 10 books. Using a proportion, we can find the cost of 1 book and then multiply it by 10 to find the cost of 10 books. This method is useful for determining the cost of any number of books, given the cost of a different number of books. Book prices can vary widely depending on factors such as the format, edition, and publisher, so it is important to carefully consider book prices when making purchases.

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The new points A', B', and C' after rotating triangle ABC 90 degrees counterclockwise about the origin and reflecting it over the x-axis are (-3,1), (0,3), and (2,4) respectively.

How rotate and reflect a point?

To rotate a point in a two-dimensional plane counterclockwise about the origin by a certain angle θ, we can use the rotation matrix. This matrix has the values of sine and cosine of the angle θ and can be used to multiply with the original point's coordinate vector to get the new coordinate vector after rotation. To reflect a point over the x-axis, we negate its y-coordinate.

Calculation the coordinates of the new points :

To rotate triangle ABC 90 degrees counterclockwise about the origin, we can use the rotation matrix:

[ cosθ -sinθ ]

[ sinθ cosθ ]

where θ is the angle of rotation, in this case 90 degrees, so we have:

[ 0 -1 ]

[ 1 0 ]

We can apply this matrix to each of the points of the triangle ABC to obtain their new coordinates after the rotation.

Then, to reflect the triangle over the x-axis, we simply negate the y-coordinate of each point.

So, to find the new points A', B', and C', we perform the following operations:

A' = (1, -3) * [ 0 -1 ] = [ (-3) (-1) ] -> reflect over x-axis -> [ (-3) 1 ]

[ 1 0 ]

B' = (3, 0) * [ 0 -1 ] = [ 0 (-3) ] -> reflect over x-axis -> [ 0 3 ]

[ 1 0 ]

C' = (4, -2) * [ 0 -1 ] = [ 2 (-4) ] -> reflect over x-axis -> [ 2 4 ]

[ 1 0 ]

Therefore, the new points are (-3,1), (0,3), (2,4).

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The error interval for the combined mass, m, of the car and the person is: [tex]$$2067.65 kg \leq m \leq 2068.75 kg$$[/tex].

The mass of the car is given as 2006 kg rounded to the nearest kilogram, which means its actual mass could be as low as 2005.5 kg or as high as 2006.5 kg.

The mass of the person is given as 62.2 kg rounded to one decimal place, which means their actual mass could be as low as 62.15 kg or as high as 62.25 kg.

To find the error interval for the combined mass of the car and the person, we need to add the upper and lower bounds of each mass:

Lower bound of combined mass: 2005.5 kg + 62.15 kg = 2067.65 kg

Upper bound of combined mass: 2006.5 kg + 62.25 kg = 2068.75 kg

Therefore, the error interval for the combined mass, m, of the car and the person is: [tex]$$2067.65 kg \leq m \leq 2068.75 kg$$[/tex].

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Based on the information, the pollster's conclusion makes sense.

To know if the pollster is right with his conclusion we must perform the following operation.

In accordance with the above, we can infer that the pollster concludes that 54% of the people surveyed are equivalent to 545 people correctly because 0.86 is a minimum margin of error for this type of statistics. In addition, it can be inferred that the pollster correctly uses the statistics and study parameters of a sample to establish a correct conclusion.

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The formula for the total number of factors for a given number is given by; Total Number of Factors for N = (a+1) (b+1) (c+1)

As a result, the percentage of adults who selected math is different from the percentage of kids who did.

As a number out of 100, a percentage is a method to express a proportion or a fraction. It is symbolized by the number %. If there are 25 boys in a class of 100 pupils, for instance, then there are 25% of boys in the class. It is a helpful method to compare quantities and to express changes in values over time.

given

120 80

Total    200

Women Overall Party A Party B

70 60

Overall    130

Therefore, there are 130 ladies in the group.

b) The chart indicates that 70 women plan to support Party A.

Thus, the percentage of adults who selected English was 40% of 48, which is equal to 0.4 times 48 and 19.2 when rounded to the closest whole number.

b) Reeshma is not accurate. The percentage of adults who selected math is 35%, while for children it is 40%, according to the pie chart.

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The complete question is:-   complete the two-way table, which shows the voting intentions of a group of men and women. a How many women are in the group?

Men

Party A Party B 120

Total    200

Women   130

Total       380

b How many women intend to vote for Party A?

2 A group of 48 adults are asked what their favourite subject was at school. They can choose from

maths, English and science.

A group of 32 school children are asked the

same question.

Answer:

The correct order to draw 65 agle would be:

C

A

B

D

The probability that among 12 randomly selected flights, exactly 10 arrive on time is 0.1667

The probability that, among 12 randomly selected flights, exactly 10 arrive on time is 0.1667. This is calculated by using the binomial probability formula:

[tex]P(x) = nCx (p^x) (1-p)^{(n-x)}[/tex]

Where:

[tex]P(x) = 12C10 (0.815^{10}) (0.185)^2 = 0.1667[/tex]

The probability that among 12 randomly selected flights, exactly 10 arrive on time is 0.1667

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Answer:

x = 9

Step-by-step explanation:

[tex]2x + 3 = 3x - 6[/tex]

[tex]3 = x - 6[/tex]

[tex]x = 9[/tex]

The solutions for the systems of inequalities are:

a) (0, -100), (0, -150), (0, -1000)

b)  (0, 50), (0, 55) , (0, 1,204).

When we have a system of inequalities, a solution is a point that solves both ienqualities at the same time.

The first one is:

y ≤ x - 8

y < -3x - 9

Here y must be smaller than x, then we can define x like x = 0, and really small values for y, like y = -100, replacing that we will get:

-100  ≤ 0 - 8 = -8

-100 < - 3*0 - 9 = -9

Both of these are true, so (0, -100) is a solution, and trivially, (0, -150) and (0, -1000) are other two solutions.

For the second system:

y > 5x + 1

y > 3

Let's do the same thing, x = 0 and y gets really large values, like y = 50

50 > 5*0 + 1 = 1  this is true.

50 > 3   this is true.

so (0, 50) is a solution, and also are (0, 55) and (0, 1,204).

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Answer:

y = 12

Step-by-step explanation:

if a tangent and a secant are drawn from an external point to a circle, then the square of the measure of the tangent is equal to the product of the measures of the secant's external part and the entire secant , that is

y² = 8(8 + 6 + 4) = 8 × 18 = 144 ( take square root of both sides )

y = [tex]\sqrt{144}[/tex] = 12

Answer:

5) 12.2       6) 2

Step-by-step explanation:

Use Pythagoras for both

Rearrange for x in question 6

Answer:

To divide 8 by 52.08, we can use long division as follows:

      0.15   (quotient)

  __________

52.08 | 8.00

      7.81   (subtract 7.81 from 8.00 to get 0.19)

     ----

      1.19   (bring down the next digit 0, and add a decimal point)

      1.04   (subtract 1.04 from 1.19 to get 0.15)

     ----

      0.15   (no more digits to bring down, and the remainder is 0)

Therefore, 8 divided by 52.08 is approximately 0.15.

We need to add 10 students to the hostel so that the food is enough for only 45 days.

Let's assume that "x" students need to be added to the hostel so that the food is enough for only 45 days.

We know that the total amount of food available is fixed, so the product of the number of students and the number of days that the food will last must also be fixed.

We can use this fact to set up an equation:

50 × 54 = (50 + x) × 45

To solve for x, we can simplify and solve for x:

Expand using FOIL method

50 × 54 = (50 + x)45

50 × 54 = 45 × 50 + 45 × x

2700 = 2250 + 45x

450 = 45x

x = 10

Therefore, number of students to be added is 10.

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Answer:

Multiplying the second equation by 5, we get:

15x + 20y = 180

Now, we can add this equation to the first equation:

26x = 208

x = 8

Substituting x = 8 in the second equation:

3(8) + 4y = 36

4y = 12

y = 3

Therefore, the solution to the system is (8, 3).

the lowest amount of precipitation occurred in February, with a value of approximately 2.32 inches.

Why it is and how to form a graph?

To find the month with the lowest amount of precipitation, we need to find the minimum value of the quadratic equation y = –0.04088x²2 + 0.4485x + 1.862.

Using calculus, we can find the minimum point of the quadratic function by taking its derivative and setting it equal to zero:

y' = -0.08176x + 0.4485

0 = -0.08176x + 0.4485

x = 5.484

This means that the minimum value of the function occurs at x = 5.484. Since x represents the month number (with January being 1), we can conclude that the month with the lowest amount of precipitation is February (the second month in the table).

To verify this, we can plug in x = 2 into the quadratic equation:

y = –0.04088(2)²2 + 0.4485(2) + 1.862

y = 2.31752

Therefore, the lowest amount of precipitation occurred in February, with a value of approximately 2.32 inches.

To graph the function, we can plot the points given in the table and connect them with a smooth curve. Here is a completed table with the missing values:

Month (x) Precipitation

January 1 2.27 inches

February 2 2.32 inches

March 3 2.57 inches

April 4 2.94 inches

May 5 3.43 inches

June 6 3.94 inches

July 7 2.72 inches

August 8 2.86 inches

September 9 2.59 inches

October 10 2.03 inches

November 11 1.46 inches

December 12 1.03 inches

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Answer:

D: December

The given model for precipitation in Phoenix, Arizona is y = –0.04088x2 + 0.4485x + 1.862, where x is the month number (1 for January, 2 for February, and so on) and y is the precipitation in inches. We can use this model to fill in the missing values in the table:

| Month (x) | Precipitation |

|-----------|---------------|

| January   | 2.27 inches   |

| February  | 2.27 inches   |

| March     | 2.24 inches   |

| April     | 2.18 inches   |

| May       | 2.09 inches   |

| June      | 1.98 inches   |

| July      | 1.84 inches   |

| August    | 1.68 inches   |

| September | 2.59 inches   |

| October   | 1.50 inches   |

| November  | 1.30 inches   |

| December  | 1.08 inches   |

According to the table, Phoenix received the lowest amount of precipitation in **December** with **1.08 inches** of precipitation, so the correct answer is **D. December**.

The statement about regression line that is true is "it indicates a linear relationship between dependent variable and independent variable(s)."

In statistics, regression is a method of modeling the connection between a dependent variable (also known as a response variable) and one or more independent variables (also known as explanatory variables or predictors). It's also known as a linear regression model.

A regression model is established in order to identify the linear relationship between the dependent variable and one or more independent variables. The line of best fit is represented by the regression line in a simple linear regression model, which represents the relationship between the dependent variable and independent variable(s).

The line of best fit is determined by minimizing the sum of the squares of the residuals (errors). The objective of the regression model is to obtain a relationship between the dependent variable and the independent variable that explains the variance of the dependent variable based on the independent variable(s).

Hence, the correct option is: it indicates a linear relationship between dependent variable and independent variable(s).

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The three positive numbers whose sum is 270 and whose product is a maximum is 67.5, 135, 67.5.

Let x, y, and z be the three positive numbers.

Write an equation relating x, y, and z based on the given constraint: x + y + z = 270.

Use algebra to solve for one of the variables in terms of the others.

Solving for z in terms of x and y: z = 270 - x - y.

Substitute the expression for z into the equation for the product of the three numbers:

P = x * y * z = x * y * (270 - x - y).

Expand the expression for P and simplify as P = 270xy - x²y - xy².

Using calculus to find the critical points of P, which occur when the derivative of P with respect to x is zero:

dP/dx = 270y - 2xy - y²= 0.

Solving for x in terms of y: x = (270y - y²)/(2y).

Simplify the expression for x as x = 135 - (y/2).

Since x and y must be positive, we know that 0 < y < 270/2 = 135.

Therefore, we can choose y = 135.

Using the equation for x in terms of y, we can find x as x = 135/2 = 67.5.

Using the constraint x + y + z = 270, we can find z as z = 67.5.

 Check that x, y, and z are positive and that they add up to 270.

Therefore, the three positive numbers whose sum is 270 and whose product is a maximum are 67.5, 135, and 67.5.

The product of these three numbers is (67.5) * (135) * (67.5) = 614062.5.

So the maximum product is 614062.5.

Thus, the answer is: 67.5, 135, 67.5.

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When the minimum volume of a clown is 60,000 cm³ and the volume of a car is 3 million cm³, 55 is an upper bound on the maximum number of clowns that can fit in a car. The correct answer is Option A.

Bounds are the maximum and minimum limits that are permitted, within which something can or must be performed. Bounds are used to refer to an acceptable range of values that provide safe operation or performance. In mathematics, a set of bounds can define the limits of the amount of things or objects.

The minimum volume of a clown is 60,000 cm³, so to fit 55 clowns in a car we need:

55 clowns × 60,000 cm³/clown = 3,300,000 cm³

This is lower than the volume of the car. Therefore, 55 is an upper bound on the maximum number of clowns that can fit in the car.

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Answer:

5x³ = 40

20x^6/4x² = 80

100 is not equal to 80

Step-by-step explanation:

5x³ = 5*2^3

      = 40

20x^6/4x² = 20*2^6/4*2^2

                 = 20*64/16

                 = 80

The approximate labor cost increase in percentage is approximately 21%, which is closest to option D.

To calculate the approximate labor cost increase in percentage, we can use the following formula:

Labor cost increase percentage = ((new labor cost - old labor cost) / old labor cost) x 100%

Plugging in the given values, we get:

Labor cost increase percentage = ((53,000 - 44,000) / 44,000) x 100%

Labor cost increase percentage = (9,000 / 44,000) x 100%

Labor cost increase percentage = 0.2045 x 100%

Labor cost increase percentage ≈ 20.45%

Therefore, the approximate labor cost increase in percentage is approximately 21%, which is closest to option D.

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The bank statement shows a loss of 70 euros, considering the profit concept.

From the table presented in this problem, the parameters are given as follows:

To calculate profit considering money in and money out, you need to subtract the total money out from the total money in.

Hence the formula for calculating profit is given as follows:

Profit = Money In - Money Out

The total money in is given as follows:

Money In = 360 + 295 + 415 = 1070.

The total money out is given as follows:

Money Out = 520 + 70 + 400 + 150 = 1140.

Hence the profit is given as follows:

Profit = Money In - Money Out

Profit = 1070 - 1140

Profit = -70 (negative profit means that it is a loss).

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Therefore, 15% of the beads on Tiana's necklace are blue.

Percentage is a way of expressing a fraction or a proportion out of 100. It is denoted by the symbol "%". For example, if we say that 50% of the students in a class are girls, it means that 50 out of every 100 students are girls.

Percentage can be calculated by dividing the given quantity by the total and multiplying by 100. For example, if there are 20 girls out of a total of 40 students in a class, the percentage of girls in the class can be calculated as follows:

Percentage of girls = (number of girls / total number of students) x 100%

= (20 / 40) x 100%

= 50%

by the question.

Tiana's necklace has a total of 3 + 17 = 20 beads.

To find the percentage of blue beads, we need to divide the number of blue beads by the total number of beads and then multiply by 100 to get the percentage:

percentage of blue beads = (number of blue beads / total number of beads) x 100

percentage of blue beads = (3 / 20) x 100

percentage of blue beads = 15

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Answer:

180

Step-by-step explanation:

Form an equation

27x+17=180

Solve it for x  

x = 6.0recurring

the perimeter is 180

Let me know if it helps