Answer:
The correct answer is = 15.
Step-by-step explanation:
Formula:
The sum of the first n terms of an arithmetic progression with first term a and constant difference d is
[tex]S_n=\dfrac{n}{2}[2a+(n-1)d[/tex]
using this formula in this problem
Solution:
The sum of the first ten terms is
[tex]S_{10}=\dfrac{10}{2}[2a+(10-1)d[/tex]
[tex]S_{10}=5(2a+9d)[/tex]
The sum of the 20th, 21st, and 22nd terms is three times the 21st term:
[tex]3a_{21}=3(a+(21-1)d)[/tex]
[tex]3a_{21}=3(a+20d)[/tex]
[tex]3a_{21}=3a+60d[/tex]
The problem then tells us
[tex]S_{10}=3a_{21}[/tex]
[tex]10a+45d=3a+60d[/tex]
[tex]7a=15d[/tex]
there are only positive integers and the first term a is less than 20 as given. Since 7 and 15 have no common factor, the only explanation of the requirements is a = 15 and d = 7. So the progression is
then, 15, 22, 29, 36, ...
The problem says to find the number of terms n for which the sum is 960:
putting value in the formula
[tex]30n+7n^{2}-7n=1920\\7n^{2}+23n-1920=0[/tex]
solving quadratic will give n = 15
thus, the correct answer is 15.
alvin is 5 years older than elga. the sum of their age is 85. what is elga age
Answer:
40 years old.
Step-by-step explanation:
We can let Elga's age equal [tex]x[/tex]. Alvin's age can be equal to [tex]y[/tex]. We can make several equations from the information we know. We know that Elga's age plus five equal's Alvin's age.
[tex]x+5=y[/tex]
We also know that the sum of their ages is 85.
[tex]x+y=85[/tex]
We can substitute [tex]x+5[/tex] for [tex]y[/tex] in the second equation since [tex]x+5=y[/tex], so we have the following equation:
[tex]x+(x+5)=85[/tex]
We can combine like terms to get
[tex]2x+5=85[/tex]
Subtracting 5 from both sides results in
[tex]2x=80[/tex]
After that, we can divide both sides by 2 to get
[tex]x=40[/tex]
Thus, Elga is 40 years old.
Answer:
e = 40
a=45
Step-by-step explanation:
a + e = 85
a = e+5
e + 5 + e = 85
2e = 80
e = 40
a=45
The radius of a sphere is increasing at a rate of 2 mm/s. How fast is the volume increasing (in mm3/s) when the diameter is 60 mm?
Answer:
22608 mm³/s
Step-by-step explanation:
Applying chain rule,
dV/dt = (dV/dr)(dr/dt)............... Equation 1
Where dV/dr = rate at which the volume is increasing
But,
V = 4πr³/3
Therefore,
dV/dr = 4πr²............... Equation 2
Substitute equation 2 into equation 1
dV/dt = 4πr²(dr/dt).............. Equation 3
From the question,
Given: dr/dt = 2 mm/s, r = 60/2 = 30 mm
Consatant: π = 3.14
Substitute these values into equation 3
dV/dt = 4×3.14×30²×2
dV/dt = 22608 mm³/s
Mr. Alvarado bought a total of 20 pounds of grass seed at the nursery for $168. He paid $9 per pound for Kentucky blue grass and $6 per pound for Tall Fescue. Which system of equations can be used to find the amount x (in pounds) of Kentucky blue grass and the amount y (in pounds) of Tall Fescue Mr. Alvarado purchased?
Answer:
K+T=20
$9K + $6T = $168
K is the Kentucky blue grass in pounds
T is the Tall fescue in pounds
Step-by-step explanation:
You can start with the first equation. We don't know the exact amounts of each but we know that there was a total of 20 pounds, and there were 2 types of grass seeds, so we can get that the amount of pounds of Kentucky blue grass(K) and the pounds of Tal Fescue(T) has a sum of 20.
K + T = 20
For the second equation we know that there is a sum of $168 so we'll start with that. Then, we know he paid $9 per pound of K so $9* the value of K is the amount paid for Kentucky blue grass total. This can be represented as 9K. We do the same for T, 6T. Since the sum of the cost of $9T and $6K must be $168 we can write this as:
$9K + $6T = $168
Suppose 47% of the population has a college degree. If a random sample of size 460 is selected, what is the probability that the proportion of persons with a college degree will differ from the population proportion by greater than 5%
Answer:
387287i32
Step-by-step explanation:
i did it
How many solutions does the nonlinear system of equations graphed below
have?
A. One
B. Four
C. Two
D. Zero
Answer:
D
Step-by-step explanation:
There is no point shared by all three graphs
If the bearing of A from B is 125.Find the bearing of B from A
Answer:
305°
Step-by-step explanation:
The bearing in the reverse direction is 180° plus the bearing in the forward direction, that is
bearing of B from A = 180° + 125° = 305°
Find the area enclosed by y1 = (x - 1)3 and y2 = x -1.
I wanted to double check the answer. The professor got something completely different.
Find area between two curves
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Answer:
0.5
Step-by-step explanation:
The "enclosed area" can be taken to mean different things. Here, we consider it to mean the finite area bounded between the two curves, regardless of which curve is higher value than the other.
The area is bounded on the interval [0, 2]. On half that interval y1 > y2; on the other half, y2 > y1. This means the integral of the area between the curves will be different for one part of the interval than for the other. (The curves are symmetric about the point (1, 0).)
The area on the interval [0, 1] is given by the integral ...
[tex]\displaystyle\int_0^1{(y_1-y_2)}\,dx=\int_0^1{((x-1)^3-(x-1))}\,dx\\\\=\int^1_0{(x(x-1)(x -2))}\,dx=\left.(\frac{x^4}{4}-x^3+x^2)\right|^1_0=\boxed{\frac{1}{4}}[/tex]
The area on the interval [1, 2] is the integral of the opposite integrand, but has the same value.
The positive area over the whole interval from 0 to 2 is 1/4+1/4 = 1/2.
If you simply integrate y2-y1 or y1-y2 over that interval, the result is 0.
Name some real-life situations where graphing could be useful. Discuss your ideas. Name some real-life situations where finding the coordinates of the midpoint of a line segment could be useful.
Answer:
mapping an area
Step-by-step explanation:
One situation and probably the most common is mapping an area. Graphs are great for dividing a geographical location into various sections and creating a model representation of the area. The graph itself allows for specific directions to be shared using the x and y coordinates on the graph. The same applies for finding the midpoint of a line segment. For example, this is useful if you were trying to find a place to meetup with a friend that is an equal distance from where you are and from where your friend is currently located. Therefore, allowing you to meetup at the midpoint.
Ed decided to build a storage box. At first, he was planning to build a cubical box with edges of length n inches. To increase the amount of storage, he decided to make the box 1 inch taller and 2 inches longer while keeping its depth at n inches. The volume of the box Ed built has a volume how many cubic inches greater than the box he originally planned to build?
Answer:
The new volume is 3n^2+2n inches greater.
Step-by-step explanation:
Volume of a cube = s^3 where s is side of cube
Original volume = n^3
Volume of a Rectangular Prism = LBH
New Volume = (n+1)(n+2)(n)= n^3+3n^2+2n
DIfference = New- original = 3n^2+2n
3/8-1/4=?
Answer ……..
Step 1: Find the LCD (Least Common Denominator)
The LCD between 4 and 8 is 8. Therefore, if I change all of the fractions to have a denominator of 8, the problem is as such:
3/8 - 2/8 = ?
Step 2: Subtract
3/8 - 2/8 = 1/8
Hope this helps!
Answer:
[tex]\frac{1}{8}[/tex] (1/8)
Step-by-step explanation:
1. The LCD & basics8·1=8
4·2=8
LCD=8
If the denominator is multiplied, the numerator also has to be multipled by the same value.
2. Solving[tex]\frac{3}{8} -\frac{2}{8} =\frac{1}{8}[/tex][tex]\frac{1}{8}[/tex]
Hope this helped! Please mark brainliest :)
One way to check on how representative a survey is of the population from which it was drawn is to compare various characteristics of the sample with the population characteristics. A typical variable used for this purpose is age. The 2010 GSS of the American adult population found a mean age 49.28 years and a standard deviation of 17.21 for its sample of 4,857 adults. Assume that we know from Census data that the mean age of all American adults is 37.2 years.
Required:
a. State the research and the null hypothesis setting for a two-tailed test.
b. Calculate the t statistics and test the null hypothesis setting alpha at .01. What did you find?
c. What is your decision about the null hypothesis? What does this tell us about how representative the sample is of the American adult population?
Answer:
a) See step by Step explanation
b) z(s) = 48.88
c) We reject H₀. The sample is not representative of American Adult Population
Step-by-step explanation:
From sample
sample mean . x = 49.28
sample standard deviationn s = 17.21
sample size n₁ = 4857
Population mean according to Census data
μ = 37.2
a) Test Hypothesis
Null Hypothesis . H₀ . x = μ = 37.2
Alternative Hypothesis Hₐ . x ≠ μ
b) We have sample size (4857) we can use normal distribution
z (c) for α = 0.01 α/2 . = 0.005 is from z-table . z(c) = 2.575
To calculate z(s) = ( x - μ ) / s /√n
z(s) = 12.08 * √4857 / 17.21
z(s) = 12.08* 69.64 / 17.21
z(s) = 48.88
z(s) > z(c)
We should reject H₀. The sample is not representative of American Adult population
WILL GIVE BRAINLIEST!!!
Write as a polynomial: 14b + 1 - 6(2 - 11b)
Answer:
80b-11
Step-by-step explanation:
14b + 1 - 6(2 - 11b)
Distribute
14b+1-12+66b
Combine like terms
80b-11
Answer:
80b - 11
Step-by-step explanation:
what is the problem ?
just multiply it out and combine terms.
14b + 1 - 6(2 - 11b) = 14b + 1 - 12 + 66b = 80b - 11
Trapezoid A B C D is shown. A diagonal is drawn from point B to point D. Sides B C and A D are parallel. Sides B A and C D are congruent. Angle C B D is 24 degrees and angle B A D is 116 degrees.
What is the measure of angle ABD in trapezoid ABCD?
24°
40°
64°
92°
Answer:
40 degrees un edge
Step-by-step explanation:
Answer:
The person above me got this correct, so the answer to this is 40! I just did the Unit Test and got a 100%!
A retired couple has up to $50,000 to invest. As their financial adviser, you recommend that they place at least $35,000 in Treasury bills yielding 1% and at most $10,000 in corporate bonds yielding 3%. Write and graph the system of equations of linear inequalities that describes the possible amounts of each investment.
Answer:
See Explanation
Step-by-step explanation:
According to the Question,
Given that, A retired couple has up to $50,000 to invest. As their financial adviser, you recommend that they place at least $35,000 in Treasury bills yielding 1% and at most $10,000 in corporate bonds yielding 3%.
Therefore,
Let, x be the amount of money invested in Treasury bills
y be the amount invested in corporate bonds
Thus, the system of equations of linear inequalities is
x + y ≤ 50000
x ≥ 35000
0 ≤ y ≤ 10000
For, the graph of the system of equations of linear inequalities describes the possible amounts of each investment.
(Please find in the attachment)
Solve the equation
tan^2 thetha-3 tan thetha+2=0 for 0
Step-by-step explanation:
[tex]\tan^2 \theta - 3\tan \theta + 2 = 0[/tex]
Let [tex]x = \tan \theta[/tex]
We can then write
[tex]x^2 -3x + 2 = 0\:\:\Rightarrow\:\:(x - 2)(x - 1) = 0[/tex]
or
[tex](\tan \theta - 2)(\tan \theta - 1) = 0[/tex]
The zeros occur when
[tex]\tan \theta = 2\:\:\:\text{or}\:\:\:\tan \theta = 1[/tex]
or when [tex]\theta = 63.4°[/tex] or [tex]\theta = 45°[/tex].
how do you write in numerals
Answer:
Basic numbersNumbers up to nine should always be written in words, anything higher than nine can be written in numerals. Alternatively, some guides suggest that if you can write the number in two words or fewer then use words rather than number.hope it's helpful for u !! stay safe ...Step-by-step explanation:
1 : a conventional symbol that represents a number. 2 numerals plural : numbers that designate by year a school or college class and that are awarded for distinction in an extracurricular activity. Other Words from numeral Synonyms Example Sentences Learn More About numeral.A numeral is a symbol or name that stands for a number. Examples: 3, 49 and twelve are all numerals. So the number is an idea, the numeral is how we write it.hope it helps.stay safe healthy and happy...i’ll give brainliest to the right answer
Answer:
First one , 0.0000805
Step-by-step explanation:
With negative exponents the decimal is moved to the left the amount of the exponent. The spaces are filled with zeros.
With positive exponents the opposite occurs. The decimal moves to the right.
when 5 is added to 2 times a number , the results is 45. find the number
Answer:i think its 20
Step-by-step explanation: 20 x 2 is 40 plus 5 is 45
Answer:
✓ x - the number 5 + 2x = 45 2x = 45 - 5 2x = 40 x = 20 5 + 2(20) = 45 5 + 40 = 45 45 = 45 Hope this helps. :-) the answer is 20
Step-by-step explanation: Algebra.com
A radioactive material is known to decay at a yearly rate proportional to the amount at each moment. There were 1000 grams of the material 10 years ago. There are 980 prams right now. What will be the amount of the material right after 20 years?
a. 10 ln 2/ln(1000/980)
b. 10^6/980
c. 980^3/10^6
d. 980^2/10^3
Answer:
Amount left is 941.95 g.
Step-by-step explanation:
initial amount = 1000 g
time = 10 years
amount left = 980 grams
Now
[tex]980 = 1000 e^{-\lambda t}\\\\e^{\lambda\times 10}= 1.02\\\\10 \lambda = ln 1.02\\\\\lambda = 1.98\times10^{-3} per year[/tex]
time t = 20 years
Let the amount is N.
[tex]980 = 1000 e^{-\lambda t}\\\\e^{\lambda\times 10}= 1.02\\\\10 \lambda = ln 1.02\\\\\lambda = 1.98\times10^{-3} per year\\N = 980 e^{- 1.98\times 10^{-3}\times 20}\\\\ln N = ln 980 - 0.0396\\\\ln N = 6.88 - 0.0396 = 6.86\\\\N = 941.95 g[/tex]
write the following sets in the set builder form C={1,4,9,16,25}
C={ check example in book}
4,3,5,9,12,17,...what is the next number?
Answer:
The next number is going to be 21
Answer:
19
Step-by-step explanation:
4 even number
3,5,7 odd numbers
14 even
17, 19, 21 even
Tracy leaves the beach at 3:00 p.m. and drives along the highway at 55 mph. One hour later, Quinn leaves the same beach and drives along the same highway in the same direction at 65 mph. How many hours will it take Quinn to catch up to Tracy?
10 hours
6.5 hours
8.5 hours
15 hours
Answer:
8.5 hours
Step-by-step explanation:
55 x 9.5 (add extra hour) = 552.5 miles
65 x 8.5 (actual time spent) = 552.5 miles
The time taken for Quinn to catch up to Tracy during the journey is 8.5 hours.
Time of motion of Tracy and QuinnThe time of motion of tracy and quinn is determined by using the following equation as shown below;
For tracy, d = 55(t + 1)
For Quinn, d = 65t
where;
55(t + 1) = 65t
55t + 55 = 65t
55 = 10t
t = 55/10
t = 5.5 hours
3 hour from noon + 5.5 hours = 8.5 hours
Learn more about time of motion here: https://brainly.com/question/2364404
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What is the inverse of function f?
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Answer:
D. f^-1(x) = 3 -7x
Step-by-step explanation:
Solve x = f(y) for y to find the inverse function.
x = f(y)
x = (3 -y)/7 . . . . . . use the function definition
7x = 3 -y . . . . . . . .multiply by 7
y = 3 -7x . . . . . . . add y-7x to both sides
Then the inverse function is ...
[tex]\boxed{f^{-1}(x)=3-7x}[/tex]
Medallia calculates and publishes various statistics concerning car quality. The dependability score measures problems experienced during the past 12 months by the owners of vehicles. Toyota had 1.02 problems per car. If you had purchased a Toyota model, what is the probability that in the past 12 months the car had. in excel
Answer:
Hence the answers are,
a) Probability that in the past 12 months the car had more than one problem = P(X > 1) is 0.2716.
b) The Probability that in the past 12 months the car had almost two problems = P( X < 2) is 0.9160.
c) The Probability that in the past 12 months the car had zero problems = P(X= 0 ) is 0.3606.
Step-by-step explanation:
Let's take X to be the number of problems per car.
By considering the given statement, X follows a Poisson Distribution with Mean (X) = 1.02.
The Poisson probability formula is :
e Pr( X = k) = e- k! k= 0,1,2...
a)
The Probability that in the past 12 months the car had more than one problem = P(X > 1)
[tex]P(X > 1) =1- P(X < 1) \\\\=1- (P(X = 0) + P(X = 1)-1.021.02 e + 1.021.02 =1-6 0!\\= 1-0.3606 + 0.3678\\= 1-0.7284\\= 0.2716[/tex]
b)
The Probability that in the past 12 months the car had almost two problems = PX < 2)
[tex]Pr(X < 2) = Pr(X = i) = Pr(X = 0) + Pr(X = 1) + Pr(X = 2)\\-1.021.020 -1.021.02 -1.021.02 e e + e + 0! 1! 2!\\= 0.3606 + 0.3678 + 0.1876\\= 0.9160[/tex]
c)
The Probability that in the past 12 months the car had zero problems = P(X= 0 )
[tex]- 1.021.02 e 0!\\= 0.3606[/tex]
Given that m∠abc=70° and m∠bcd=110°. Is it possible (consider all cases): Line AB intersects line CD?
The line AB and CD are parallel. Then it is impossible that the line AB intersects the line CD.
What are parallel lines?When the distance between the lines is constant, then the lines are called parallel lines. The lines do not intersect when they are separated from each other. And the slope of the lines is equal.
Given that ∠ABC = 70° and ∠BCD = 110°.
Then the line AB and the line CD makes the same angle with the line BC.
Hence, the line AB and CD are parallel.
Then it is impossible that the line AB intersects the line CD.
More about the parallel lines link is given below.
https://brainly.com/question/16701300
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write expanded notion of 752 863?
Answer:
7 hundred thousands, 5 ten thousands, 2 thousands, 8 hundreds, 6 tens, 3 ones
Step-by-step explanation:
to write a number in expanded notation all you need to do is write out the number in words.
A triangle has vertices at L(2, 2), M(4,4), and N(1,6).
The triangle is transformed according to the rule Ro.
Which statements are true regarding the
transformation? Select three options.
180
The rule for the transformation is (x, y) (-X, -y).
The coordinates of L'are (-2,-2).
The coordinates of Mare (-4,4).
The coordinates of N' are (6,-1).
The coordinates of N'are (-1,-6).
Answer:
The rule for the transformation is (x, y) (-x, -y).
The coordinates of L'are (-2,-2).
The coordinates of N'are (-1,-6).
Step-by-step explanation:
Given
[tex]L = (2,2)[/tex]
[tex]M = (4,4)[/tex]
[tex]N = (1,6)[/tex]
[tex]Ro=180[/tex]
Required
Select three options
The rule to this is:
[tex](x,y) \to (-x,-y)[/tex]
So, we have:
[tex]L = (2,2)[/tex]
[tex]L' =(-2,-2)[/tex]
[tex]M = (4,4)[/tex]
[tex]M =(-4,-4)[/tex]
[tex]N = (1,6)[/tex]
[tex]N' = (-1,-6)[/tex]
I need help solving this problem. Thanks
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Answer:
f = 2T/(v1 +v2)
Step-by-step explanation:
Multiply by the inverse of the coefficient of f.
[tex]T=f\cdot\dfrac{v_1+v_2}{2}\\\\f=\dfrac{2T}{v_1+v_2}[/tex]
Use the parametric equations of an ellipse, x=acosθ, y=bsinθ, 0≤θ≤2π , to find the area that it encloses.
Answer:
Area of ellipse=[tex]\pi ab[/tex]
Step-by-step explanation:
We are given that
[tex]x=acos\theta[/tex]
[tex]y=bsin\theta[/tex]
[tex]0\leq\theta\leq 2\pi[/tex]
We have to find the area enclose by it.
[tex]x/a=cos\theta, y/b=sin\theta[/tex]
[tex]sin^2\theta+cos^2\theta=x^2/a^2+y^2/b^2[/tex]
Using the formula
[tex]sin^2x+cos^2x=1[/tex]
[tex]\frac{x^2}{a^2}+\frac{y^2}{b^2}=1[/tex]
This is the equation of ellipse.
Area of ellipse
=[tex]4\int_{0}^{a}\frac{b}{a}\sqrt{a^2-x^2}dx[/tex]
When x=0,[tex]\theta=\pi/2[/tex]
When x=a, [tex]\theta=0[/tex]
Using the formula
Area of ellipse
=[tex]\frac{4b}{a}\int_{\pi/2}^{0}\sqrt{a^2-a^2cos^2\theta}(-asin\theta)d\theta[/tex]
Area of ellipse=[tex]-4ba\int_{\pi/2}^{0}\sqrt{1-cos^2\theta}(sin\theta)d\theta[/tex]
Area of ellipse=[tex]-4ba\int_{\pi/2}^{0} sin^2\theta d\theta[/tex]
Area of ellipse=[tex]-2ba\int_{\pi/2}^{0}(2sin^2\theta)d\theta[/tex]
Area of ellipse=[tex]-2ba\int_{\pi/2}^{0}(1-cos2\theta)d\theta[/tex]
Using the formula
[tex]1-cos2\theta=2sin^2\theta[/tex]
Area of ellipse=[tex]-2ba[\theta-1/2sin(2\theta)]^{0}_{\pi/2}[/tex]
Area of ellipse[tex]=-2ba(-\pi/2-0)[/tex]
Area of ellipse=[tex]\pi ab[/tex]
please help me in math
Answer:
4x/3Step-by-step explanation:
Let the area of initial square is x, then shaded squares will have area as geometric sequence:
x/4, x/16, x/64, ...The first term is x, the common ratio is 1/4
Sum of infinite GP is:
S = a/(1 - r)By substituting values we get:
S = x/(1 - 1/4) = x / (3/4) = 4x/3