Answer:
A.
Step-by-step explanation:
When we multiply the 2 negatives together, we will get a positive number. Since choice A, when you multiply them together, you will get a positive number. Therefore, your answer choice is A.
Answer:
A. [tex]- \frac{-19}{-8} (-50)[/tex]
Step-by-step explanation:
The product between two negative numbers is a possitive number. Then, if we multiply (-8) in the denominator by the (-1) we get:[tex]- \frac{-19}{-8} (-50)=\frac{-19}{-8\times{(-1)}} (-50)=\frac{-19}{8}(-50)[/tex], which equals the expression above.A standard 52-card deck of French playing cards consists of four suits: hearts, spades, clubs, and diamonds. There are 13 cards of each suit; each suit has cards of rank 2 through 10, along with an ace, king, queen, and jack. Typically, hearts and diamonds are the red suits, while spades and clubs are the black suits. Four cards are drawn from the deck, one at a time, without replacement. a) The second card drawn is from a red suit. Based on this information, what is the probability it is a heart
Answer:
P = 0.5
Step-by-step explanation:
Let's call A the event that the second card is red suit and B the event that the second card is a heart.
So, the probability that the second card is a heart given that is a red suit is calculated as:
P(B/A) = P(A∩B)/P(A)
Additionally, the probability P(A∩B) that the second card is a red suit and is a heart is equal to the probability P(B) that the second card is a heart. So,
P(B/A) = P(B)/P(A)
Then, P(A) is equal to 0.5 because half of the cards are red cards and P(B) is equal to 0.25 because a quarter of the cards are red. Finally, P(B/A) is equal to:
P(B/A) = 0.25/0.5 = 0.5
if P degree,2P degree and 3p degree are the angles of a triangle find them
Answer:
p+2p+3p=180degree(sum of angle of triangle)
6p=180degree
p=180degree/6
p=30degree
here your answer and please support me
Answer:
30, 60, 90
Step-by-step explanation:
p+2p+3p= 180
6p= 180
p=30, 2p= 60, 3p= 90
A survey of 700 non-fatal accidents showed that 143 involved faulty equipment. Find a point estimate for p, the population proportion of accidents that involved faulty equipment. Group of answer choices
Answer:
The point estimate for p is 0.2043.
Step-by-step explanation:
The point estimate for the population proportion of accidents that involved faulty equipment is the number of acidents which involved faulty equipment divided by the number of accidents surveyed.
In this question:
700 accidents surveyed
143 involved faulty equipment
143/700 = 0.2043
The point estimate for p is 0.2043.
What is the slope of a line perpendicular to y=-7X?
O A.
4
B.
IN
N
O c.
4
O D.
PLZZZ HELP
Answer:
1/7
Step-by-step explanation:
y=-7X
The slope of this line is -7
Perpendicular lines have slopes that multiply to -1
-7 * m = -1
Divide each side by -7
m = -1 / -7
m = 1/7
The slope of the perpendicular line is 1/7
Answer:
1/7
Step-by-step explanation:
Perpendicular slope can be calculated by take the opposite/negative reciprocal of the given slope. This means multiply the given slope by -1 (so if it is negative it becomes positive and if it is positive then becomes negative) and then flip the numerator and denominator.
So -7 is the slope of the given equation (y = mx + b where is m is slope and b is the y-intercept).
to find perpendicular slope..
Step 1. Multiple -7 by -1 = 7
Step 2. Flip 7/1 to 1/7
Answer: 1/7 is perpendicular slope
pls pls help me help me
It is D.
you must multiply the second equation by 3, so that the +3y in the first equation can cancel out the (now) -3y in the second equation.
what is the remainder when x+ - 2x2 – 3x – 7 is divided by x + 2?
x+-2*2-3x-7
x+4-3x-7
x+1.x-7
x.x-7
2x-7
Pablo Picasso is making one color version of all his paintings. He uses the colors in the following order and then starts over from the begining red, blue, pink, green, and purple. What color is painting 27
Answer:
The answer is blue
Step-by-step explanation:
There are five colors. So count by fives until you hit 25.
red, blue, pink, green, and purple. 5
red, blue, pink, green, and purple. 10
red, blue, pink, green, and purple. 15
red, blue, pink, green, and purple. 20
red, blue, pink, green, and purple. 25
Then count to 27.
red, blue. 27
So it is blue.
This question is determined by using simple mathematics tricks . Therefore, the color is blue on painting 27.
Given:
The order of painting begin from the red, blue, pink, green, and purple.
We need to determined the color of 27 painting.
According to question,
There are five colors for painting, count by fives until you hit 25.
Now, count the colors,
red, blue, pink, green, and purple - 5
red, blue, pink, green, and purple - 10
red, blue, pink, green, and purple - 15
red, blue, pink, green, and purple - 20
red, blue, pink, green, and purple - 25
Now at 26 there is red and at 27 there is blue color.
Therefore, the color is blue on painting 27.
For further details, please prefer this link:
https://brainly.com/question/4271236
Find the dimensions of a rectangle with perimeter 92 m whose area is as large as possible. (If both values are the same number, enter it into both blanks.) g
Answer:
The dimensions are x = 23 and y = 23
The maximum area of the rectangle A = 529
Step-by-step explanation:
Step(i):-
Let given function area of the rectangle
A = x y ....(i)
Given Perimeter of rectangle
2 ( x + y ) = 92
(x +y ) = 46
y = 46 - x ....(ii)
Substitute y = 46 - x in equation (i)
A = x (46 - x)
A = 46 x - x² ....(iii)
Differentiating equation (iii) with respective to 'x'
[tex]\frac{dA}{dx} = 46(1) - 2 x[/tex] ...(iv)
Step(ii):-
[tex]\frac{dA}{dx} = 46(1) - 2 x = 0[/tex]
46 - 2 x = 0
46 = 2 x
x = 23
Again Differentiating equation (iv) with respective to 'x'
[tex]\frac{d^{2} A}{dx^{2} } = - 2 (1) = -2 < 0[/tex]
The maximum value at x = 23
Step(iii):-
From(ii)
y = 46 - x
y = 46 - 23
y = 2 3
The dimensions are x = 23 and y = 23
Final answer :-
The dimensions are x = 23 and y = 23
The maximum area of the rectangle
A = x y
A = 23 ×23
A = 529
The maximum area of the rectangle = 529
The dimension of the rectangle with perimeter 92 m whose area is as large as possible is 23m by 23m
If the perimeter of a rectangle is 92m, hence;
2(x+y) = 92
x is the length
y is the width
x + y = 46 ....... 1
If the area is as large as possible, hence;
xy = maximum .........2
From equation 1, x = 46 - y
Substitute into the second equation
(46-y)y = P(y)
P(y) = 46y - y²
If the product is at the maximum, hence;
dP/dy = 46 - 2y = 0
46 - 2y = 0]
2y = 46
y = 23
Since x + y = 46
x = 46 - y
x = 46 - 23
x = 23
Hence the dimension of the rectangle with perimeter 92 m whose area is as large as possible is 23m by 23m
Learn more here: https://brainly.com/question/13598452
If the distribution of weight of newborn babies in Maryland is normally distributed with a mean of 3.89 kilograms and a standard deviation of 0.68 kilograms, find the weights that correspond to the following Z-scores. Round your answers to the nearest tenth, if necessary. (a) z = -1.35 kilograms (b) z = 2.64 kilograms
Answer:
a) 3 kilograms
b) 5.7 kilograms
Step-by-step explanation:
Z-score:
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question:
[tex]\mu = 3.89, \sigma = 0.68[/tex]
We have to find X for both values of Z.
a) z = -1.35
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-1.35 = \frac{X - 3.89}{0.68}[/tex]
[tex]X - 3.89 = -1.35*0.68[/tex]
[tex]X = 3[/tex]
3 kilograms
b) z = 2.64
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]2.64 = \frac{X - 3.89}{0.68}[/tex]
[tex]X - 3.89 = 2.64*0.68[/tex]
[tex]X = 5.7[/tex]
5.7 kilograms
Red beads cost $1 an ounce and gold beads cost $3
an ounce. Juanita wants to purchase a 12-ounce
mixture of red and gold beads that she can sell for $2
an ounce. The solution of the system shows the
number of beads needed for Juanita to break even.
x + y = 12
x + 3y = 24
How many ounces of red beads will Juanita buy to
break even?
How many ounces of gold beads will she buy?
Answer:
6 ounces of red beads
6 ounces of gold beads
Step-by-step explanation:
x + y = 12
x + 3y = 24
We can solve this with substitution or elimination. In this case, I would suggest elimination. Subtract the first equation from the second:
2y = 12
y = 6
Plug back into either equation to find x.
x = 6
Answer:
How many ounces of red beads will Juanita buy to break even?
6
How many ounces of gold beads will she buy?
6
Step-by-step explanation:
Because I got 100 percent on EDG 2020
helppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp
Answer:
The picture on the bottom right.
Step-by-step explanation:
There are eight compartments and seven of it is shaded and the other one five of the eight compartments are shaped.
I hope this helps :)
This question has several parts that must be completed sequentially. If you skip a part of the question, you will not receive any points for the skipped part, and you will not be able to come back to the skipped part.
Tutorial Exercise Find the indefinite integral.
a) dx3x 2 + 2
b) x3 + 2x
c) dx6x 5 + 5
d) x6 + 5x
Answer:
a.) dx3x² + 2
Use the properties of integrals
That's
integral 3x² + integral 2
= 3x^2+1/3 + 2x + c
= 3x³/3 + 2x + c
= x³ + 2x + C
where C is the constant of integration
b.) x³ + 2x
Use the properties of integrals
That's
integral x³ + integral 2x
= x^3+1/4 + 2x^1+1/2
= x⁴/4 + 2x²/2 + c
= x⁴/4 + x² + C
c.) dx6x 5 + 5
Use the properties of integrals
That's
integral 6x^5 + integral 5
= 6x^5+1/6 + 5x
= 6x^6/6 + 5x
= x^6 + 5x + C
d.) x^6 + 5x
integral x^6 + integral 5x
= x^6+1/7 + 5x^1+1/2
= x^7/7 + 5/2x² + C
Hope this helps
How many meters make a centimeter
Answer:
There are 0.01 meters in a centimeter.
Step-by-step explanation:
cent means 100th
Hope this helps :)
17. Write the greatest and the smallest 4-digit numbers using four different digits
with the conditions as given:
( Digit 7 is always at units place.
Answer:
Greatest number = 9867
Smallest number = 1027
Step-by-step explanation:
Greatest number:
- - - 7
In order to form the greatest number, we should simply put the greatest available digit at the thousands place, the second greatest at the hundreds place and the third greatest at the tens place (which would be 9, 8, and 6 respectively).
9867
Smallest number:
- - - 7
In order to form the greatest number, we should simply put the lowest available digit at the thousands place (excluding zero since a number can't start with a zero), put zero at the hundreds place and the third lowest at the tens place (which would be 1, 0, and 2 respectively).
1027
Stuck on this one, help asap please
Answer:
Tan B = 24/10 = 12/5
Step-by-step explanation:
Tangent is opposite/adjacent. The side opposite of B is 24 and adjacent to that is 10.
Use Stokes' Theorem to calculate the circulation of the field F around the curve C in the indicated direction. F = 3yi + yj+zk
C: counterclockwise path around the boundary of the ellipse x2/4+y2/64=1
Answer:
[tex]\int \int \bigtriangledown F\ X\ dS = \int F\cdot dr[/tex] = 12π
Step-by-step explanation:
The field F is given by:
[tex]F = 3y\hat{i} + y\hat{j}+z\hat{k}[/tex] (1)
The curve C is the ellipse:
[tex]\frac{x^2}{4}+\frac{y^2}{64}=1\\\\(\frac{x}{2})^2+(\frac{y}{8})^2=1[/tex]
In order to calculate the circulation of F around the curve C, you first find the parametric equation for the given ellipse.
The general form of an ellipse equation is:
[tex](\frac{x}{a})^2+(\frac{y}{b})^2=1[/tex]
The parametric equation is:
[tex]r(t)=acost \hat{i} + bsint\hat{j}=2cost\hat{i}+8sint\hat{j}[/tex] (2)
The Stokes's theorem is given by the following identity:
[tex]\int \int \bigtriangledown F\ X\ dS = \int F\cdot dr[/tex]
The path integral is also:
[tex]\int F\cdot dr=\int F(r(t))\cdot dr(t)[/tex] (3)
For F(r(t)) and dr(t) you obtain:
[tex]F(r(t))=3(8sint)\hat{j}+(8sint)\hat{j}+(z)\hat{k}\\\\dr(t)=(-2sint\hat{i}+8cost\hat{j}+0\hat{k})dt\\\\F(r(t))\cdot dr(t)=(-48sin^2t+64cos^2t)dt[/tex]
Next, in the equation (3) you obtain:
[tex]\int_0^{2\pi} (-48sin^2t+64cos^2t)dt=\int_0^{2\pi}(-\frac{48}{2}(1-cos2t)+\frac{64}{2}(1+cos2t))dt\\\\=\int_0^{2\pi}(-24+24cos2t+32+32cos2t)dt\\\\=\int_0^{2\pi}(6+56cos2t)dt\\\\=[6t+56sin2t]_0^{2\pi}=[6(2\pi)-0]=12\pi[/tex]
The circulation of the field around C is 12π
Find the path of the numbers from the upper left corner to the bottom right corner. The sum of the numbers must be equal to the number at the exit arrow. You are allowed to move either down or to the right only.
Answer: 80> 6> 95 > 2> 69> 23> 5
Step-by-step explanation:
80 + 6 + 95 + 2 + 69 + 23 + 5 = 280
A random sample of 11 students produced the following data, where x is the hours spent per month playing games, and y is the final exam score (out of a maximum of 50 points). The data are presented below in the table of values. x y 14 46 15 49 16 37 17 42 18 37 19 31 20 25 21 23 22 20 23 15 24 12 What is the equation of the regression line?
Answer:
y= -3.7x+100.94
Step-by-step explanation:
Generally this type of problems is solved by using a calculator or a spreadsheet. Now, getting the final equation depends on the model of calculator you are using, so I will suggest you look for the instructions on your calculator's instruction manual. I'll provide indications for using excel.
So first you need to input the table on an excel sheet. You can input them just the same way they were given to you. (See attached picture)
Once you inputed them, you can highlight them and go to the insert tab. There you can pick the scattering plot option. Once the scatterplot is graphed, you can right-click on the graph and a menu should appear. Pick the option add tendency line. Choose the line option and below, you can mark the option present equation on the graph and present the value of R. And that will be it! Excel will automatically provide you with the equation of the regression line you need.
Most scientific calculators nowaday can provide you with the equation, you just need to input the data and they will return the slope and y-intercept of the line.
There are other formulas you can use to find this regression by hand, but they are generally used in statistics courses.
The water was pumped out of a backyard pond. What is the domain of this graph?
What is the volume of a sphere, to the nearest cubic inch, if the radius is 7 inches? Use π = 3.14.
Answer:
[tex]V=\frac{4}{3}\pi r^{2}[/tex]
=[tex]\frac{4}{3}[/tex] x [tex]\pi[/tex] x [tex]7^3[/tex]
= 1436.755040
Volume = 1436.755040
Step-by-step explanation:
Answer:
1436.03 in³
Step-by-step explanation:
We can use the formula V = [tex]\frac{4}{3}[/tex][tex]\pi[/tex]r³
Plug in 7 for r:
V = [tex]\frac{4}{3}[/tex][tex]\pi[/tex](7)³
Plug in 3.14 for pi:
V = [tex]\frac{4}{3}[/tex](3.14)(343)
V = 1436.03 in³
I'm having trouble finding the missing number. Please simplify the resulting fraction. Thank you in advance. : 0) 7/8 = ?/48
Answer:
42
Step-by-step explanation:
7/8 = x / 48
We need to get a common denominator
Multiply the left side by 6
7/8 *6/6 = x/48
42/48 = x/48
Since the denominators are equal, the numerators must be equal
42 =x
Answer:
42
Step-by-step explanation:
7/8=42/48
Cross products: 7(48)=8x
PLEASE HELP!!!! Seventeen consecutive positive integers have a sum of 306. What is the sum of the seventeen consecutive integers that immediately follow the seventeen positive integers that sum to 306?
Answer:
595
Step-by-step explanation:
Let the first integer be n. Then each consecutive integer will be (n+1), (n+2)... until (n+16).
First, from the formula [tex]k/2(a+x_{k})[/tex], where k is the number of elements and xk is the last element, we can find 1+2+3 ... +15+16 = (16/2)(1+16)=136.
Anyways, this means that 17n+136=306.
We can find that n=10
Thus, the first integer is 10, and the 17th integer will be 10+16=26.
Thus, the first integer immediately proceeding 26 is 27. There are a total of 17 digits including 27 so we can add 16 to 27 to find the last digit, which is 43. There are again 17 digits in this set.
Thus, we have: 17/2(27+43)=595.
Find X. Please help.
Answer:
22.62°
Step-by-step explanation:
tan x = 5/12
tan x = 0.416666667
x = arctan(0.416666667)
x = 22.61986983
x = 22.62°
Suppose you do an experiment where you roll a standard die twice. You decide to keep performing this experiment unless you get a sum of the rolls to be exactly 6. How many times do you feel you have to do this experiment on an average?
Answer:
7.2 times
Step-by-step explanation:
There are 36 possible outcomes when rolling a die twice and adding the results. The outcomes for which the sum is 6 are:
Sum = 6: {1,5; 2,4; 3,3; 4,2; 5,1}
Therefore there is a 5 in 36 chance that the sum will be 6.
The expected number of trials to achieve that result is given by:
[tex]E = \frac{36}{5}\\E=7.2\ times[/tex]
On average, it would take 7.2 trials to achieve a sum of 6.
Describe the shape of the graph f(x)=x
Answer:
The shape of the graph of f(x)=x is that of a linear function.
Step-by-step explanation:
The graph f(x)=x is the parent function of the linear function. It is a positive function since it goes upward from left to right, and it passes through the point of (0,0). It also has a slope of 1, which is the slope of the parent function, or the graph of f(x)=x. Note once again: The parent linear function and the graph of f(x)=x are the exact same graph.
The shape of the graph of function f(x) = x is that of a linear function.
How to find the function which was used to make graph?There are many tools we can use to find the information of the relation which was used to form the graph. A graph contains data of which input maps to which output. Analysis of this leads to the relations which were used to make it.
The graph of a function f(x)=x is the parent function of the linear function.
This is a positive function since it goes upward from left to right, and it passes through the point of (0,0).
And also has a slope of 1, which is the slope of the parent function, or the graph of f(x)=x.
Hence, the parent linear function and the graph of f(x)=x are the exact same graph.
Learn more about finding the graphed function here:
https://brainly.com/question/27330212
#SPJ2
Se x .y = 2 e x + y = 9, então x² + y² é :
a) 76
b) 167
c) 77
d) 169
e) 85
Classifique cada sentença em verdadeira ou falsa:
( ) ( a +b )² = a² + 2ab + b²
( ) ( a - b )² = a² - 2ab + b²
( ) ( a + b ) .( a – b) = a² + b²
( ) ( a +b)³ = a³ + 3a²b + 3ab² + b³
( ) ( a -b)³ = a³ - 3a²b + 3ab² - b³
Fatore cada polinômios de acordo com o caso:
a) m² - 14am + 49a² =
b) m2 – 9n² =
c) 30+ 5xy + 12a +2axy =
d) 8a²b + 10ab²
Answer:
1. A resposta é a opção C.
2. ( a +b )² = a² + 2ab + b² Verdade
( a - b )² = a² - 2ab + b² Verdade
( a + b ) .( a – b) = a² + b² Falso
( a +b)³ = a³ + 3a²b + 3ab² + b³ Verdade
( a -b)³ = a³ - 3a²b + 3ab² - b³ Verdade
3. a.) m² - 14am + 49a² = ( m - 7a)²
b) m2 – 9n² = m² - (3n)² = (m + 3n)(m - 3n)
c) 30+ 5xy + 12a +2axy = (6 + xy)(5 + 2a)
d) 8a²b + 10ab² = 2ab( 4a + 5b)
Espero que isso ajude você
Geometry please help. What is the perimeter of XYZ
Answer:
39
Step-by-step explanation:
Angle AQC, AQB and BQC are 120deg. (360/3=120). Therefore, Angle BZC, CXA and AYB are 60deg. Because, angle BZC is half of angle BQC. same for the other three angles. As, all 3 angles are 60deg, it is an equilateral triangle. So, YZ is 13 therefore as all 3 sides are equal its 13*3=39.
The solution is: 39 is the perimeter of XYZ.
What is an angle?In Plane Geometry, a figure which is formed by two rays or lines that shares a common endpoint is called an angle. The two rays are called the sides of an angle, and the common endpoint is called the vertex.
Here, we have,
Angle AQC, AQB and BQC are 120deg.
(360/3=120).
Therefore, Angle BZC, CXA and AYB are 60deg.
Because, angle BZC is half of angle BQC.
same for the other three angles.
As, all 3 angles are 60deg, it is an equilateral triangle.
So, YZ is 13
therefore as all 3 sides are equal
its 13*3=39.
Hence, 39 is the perimeter of XYZ.
To learn more on angle click:
brainly.com/question/28451077
#SPJ2
Suppose the claim size of an auto collision insurance, X, is uniformly distributed on the interval $1,000 to $10,000. What is the percent reduction in the expected claim payment by the insurer if a policyholder has a $2,000 deductible
Answer:
35.35%
Step-by-step explanation:
If there were no deductibles, the expected claim payment would be:
[tex]E(X) = \frac{10,000 +1,000}{2} \\E(X) =\$5,500[/tex]
If the collision insurance claim is under $2,000, then the insurer would not pay anything, but if X > $2,000, then the insurer would pay X - $2,000. The new expected value is:
[tex]E_2(X)=\frac{2,000-1,000}{10,000-1,000} *0+\frac{10,000-2,000}{10,000-1,000}*\frac{(2,000-2,000)+(10,000-2,000)}{2} \\E_2(X)=\frac{8}{9}*\frac{0+8,000}{2}\\ E_2(X)=\$3,555.56[/tex]
The percentage reduction on the claim payment is:
[tex]P=(1-\frac{E_2(X)}{E(X)})*100 \\P=(1-\frac{3,555.56}{5,500})*100\\P=35.35\%[/tex]
There was a 35.35% reduction.
Evaluate 9 x 8 = (10 x 8) - ( blank x 8) =80 - blank = blank
Answer:
see below
Step-by-step explanation:
9 x 8 = (10 x 8) - ( blank x 8) =80 - blank = blank
We are replacing 9 with 10 minus something
9 = 10 -1
9 x 8 = (10 x 8) - ( 1 x 8)
80 - 8
72
Eighteen telephones have just been received at an authorized service center. Six of these telephones are cellular, six are cordless, and the other six are corded phones. Suppose that these components are randomly allocated the numbers 1, 2, . . . , 18 to establish the order in which they will be serviced. (Round your answers to four decimal places.)
(a) What is the probability that all the cordless phones are among the first twelve to be serviced?
(b) What is the probability that after servicing twelve of these phones, phones of only two of the three types remain to be serviced?
(c) What is the probability that two phones of each type are among the first six serviced?
Answer:
a) 0.0498
b) 0.1489
c) 0.1818
Step-by-step explanation:
Given:
Number of telephones = 6+6+6= 18
6 cellular, 6 cordless, and 6 corded.
a) Probability that all the cordless phones are among the first twelve to be serviced:
12 are selected from 18 telephones, possible number of ways of selection = ¹⁸C₁₂
Then 6 cordless telephones are serviced, the remaining telephones are: 12 - 6 = 6.
The possible ways of selecting thr remaining 6 telephones = ¹²C₆
Probability of servicing all cordless phones among the first twelve:
= (⁶C₆) (⁶C₁₂) / (¹⁸C₁₂)
[tex] = \frac{1 * 924}{18564} [/tex]
[tex] = 0.0498 [/tex]
b) Probability that after servicing twelve of these phones, phones of only two of the three types remain to be serviced:
Here,
One type must be serviced first
The 6 remaining to be serviced can be a combination of the remaining two types.
Since there a 3 ways to select one type to be serviced, the probability will be:
= 3 [(⁶C₁)(⁶C₅) + (⁶C₂)(⁶C₄) + (⁶C₃)(⁶C₃) + (⁶C₄)(⁶C₂) + (⁶C₅)(⁶C₁)] / ¹⁸C₁₂
[tex] = \frac{3 * [(6)(6) + (15)(15) + (20)(20) + (15)(15) + (6)(6)]}{18564}[/tex]
[tex] = \frac{2766}{18564} [/tex]
[tex] = 0.1489 [/tex]
c) probability that two phones of each type are among the first six:
(⁶C₂)³/¹⁸C₆
[tex] \frac{3375}{18564}[/tex]
[tex] =0.1818 [/tex]