Answer: [tex]n=13[/tex]
Step-by-step explanation:
Given
Sum of the first 10 terms is equal to sum of 20, 21, and 22 term
[tex]\Rightarrow \dfrac{10}{2}[2a+(10-1)d]=[a+19d]+[a+20d]+[a+21d]\\\\\Rightarrow 5[2a+9d]=3a+60d\\\Rightarrow 10a+45d=3a+60d\\\Rightarrow 7a=15d[/tex]
No of terms to give a sum of 960
[tex]\Rightarrow 960=\dfrac{n}{2}[2a+(n-1)d]\\\\\Rightarrow 1920=n[2a+(n-1)\cdot \dfrac{7}{15}a]\\\\\Rightarrow 28,800=n[30a+7a(n-1)]\\\\\Rightarrow a=\dfrac{28,800}{n[30+7n-7]}\\\\\Rightarrow a=\dfrac{28,800}{n[23+7n]}[/tex]
Value of first term is less than 20
[tex]\therefore \dfrac{28,800}{n[23+7n]}<20\\\\\Rightarrow 28,800<20n[23+7n]\\\Rightarrow 0<460n+140n^2-28,800\\\Rightarrow 140n^2+460n-28,800>0\\\\\Rightarrow n>12.79\\\\\text{For integer value }\\\Rightarrow n=13[/tex]
Answer:
15
Step-by-step explanation:
In the previous answer halfway through they used the equation: 960 = (n÷2)×(2a+(n-1)×(7a÷15))
Using this equation we can substitute an number to replace n, the higher the number is the smaller a would be.
When we substitute 15 into a, then it leaves us with the answer to be a = 15 which is a positive integer and also is smaller than 20, this then let’s us know that 15 is how many terms can be summed up to make 960.
To double check this answer you can find that d = 7 by changing the a into 15 in the formula 7a/15 (found in the previous answer.
Then in the expression: (n÷2)×(2a+(n-1)×d)
substitute:
n = 14 (must be an even number for the equation to work)
a = 15
d = 7
This will give you an answer of 847, but this is only 14 terms as we changed n into 14. To add the final term you need to complete the following equation: 847+(a+(n-1)×d)
substituting:
n = 15
a = 15
d = 7
This will give you the answer of 960, again proving that it takes 15 terms to sum together to make the number 960.
I hope this has helped you.
P.S. Everything in the previous solution was right apart from the start of the last section and the answer
find out the Range coefficient of the range
marks number of students
20-29 8
30-39 12
40-49 20
50-59 7
60-69 3
Answer:
0.4494
Step-by-step explanation:
Given :
marks number of students
20-29 8
30-39 12
40-49 20
50-59 7
60-69 3
The range Coefficient is obtained thus :
Range Coefficient = (Xm - Xl) / (Xm + Xl)
Where ;
Xm = Mid value of highest class = (60+69)/2 = 64.5
Xl = Mid value of lowest class = (20+29)/2 = 24.5
Range Coefficient = (64.5 - 24.5) / (64.5 + 24.5)
Range Coefficient = 40 / 89 = 0.4494
help asap! Might be easy for some of you
Answer:
51
Step-by-step explanation:
(-3)^4-5(5)+6(5)÷(-3)(2)
81-25+30÷-6
81-25-5
81-30
51
(Remember order of operations-PEMDAS)
please i need help with this rn
Hi there!
[tex]\large\boxed{f(9) = 12}[/tex]
Evaluating f(x) at x = 9 means we must use the piecewise function where x = 9 is included.
f(x) = 12 includes 9 because a "≤" is inclusive of the interval. Thus:
f(9) = 12
At an intersection, the red light times are normally distributed with a mean time of 3 minutes and a standard deviation of 0.25 minutes. Approximately what percent of red lights last between 2.5 and 3.5 minutes? (2 points)
Answer:
95.4%
Step-by-step explanation:
Z(low)=-2 0.022750132
Z(upper)=2 0.977249868
1) Write an equation in slope-intercept form of the line with slope of 6 and y-intercept of -3. Then graph the line. 2) Write an equation in point-slope form of the line with slope -3/5 that contains(-10 ,8). Then graph the line.
Answer:
An equation in the slope-intercept form is:
y = a*x + b
Where a is the slope, and b is the y-intercept.
a)
Here we have a slope of 6 and a y-intercept of -3
Then the equation is:
y = 6*x - 3
Now we want to graph this.
To graph it, we first need to find two points (x, y) that belong to this equation, then we can graph the points, and connect them with a line.
To find the points, we evaluate in two different values of x.
x = 0
y = 6*0 - 3 = -3
Then we have the point (0, -3)
x = 1
y = 6*1 - 3 = 3
Then we have the point (1, 3)
The graph of this line can be seen in the image below (the red one)
b) Similar to before, here the slope is -3/5, then the equation is something like:
y = (-3/5)*x + b
Now we also know that the line passes through the point (-10, 8)
This means that when x = -10, we must have y = 8
Replacing these two in the equation we get:
8 = (-3/5)*-10 + b
8 = 6 + b
8 - 6 = 2 = b
Then this equation is:
y = (-3/5)*X + 2
The graph can be found in the same way as before, the graph of this function can also be seen in the image below (the green one)
Compare the subtraction problems (6/8-5/8=1/8) and (6/9-7/9=-1/9) why is the answer to the first problem positive nad the answer to the second problem negative select all that apply
6/9 - 7/9 = -1/9
is a negative number.
Leora wants to paint the nursery in her house. The nursery is an 8–by–10–foot rectangle, and the ceiling is 10 feet tall. There is a 3–by–6.5–foot door on one wall, a 3–by–6.5–foot closet door on another wall, and one 2–by–3.5–foot window on the third wall. The fourth wall has no doors or windows. If she will only paint the four walls, and not the ceiling or doors, how many square feet will she need to paint?
Answer:
The correct answer is - 242 ft^2
Step-by-step explanation:
Given:
one door : 3*6.5 => 19.5 ft^2
other door: 3*6.5 => 19.5 ft^2
a window: 2*3.5 => 7 ft^2
total = 46 ft^2
area of all four walls: 2h (l+b)
= 2(8) (10+8)
= 16 (18)
= 288 ft^2
paint required excluding doors and window:
=> area of your wall - (area of doors and window)
=> 288 - 46
= 242 ft^2
Which of these figures has rotational symmetry?
Hello!
The answer is a.
Good luck! :)
What piece of information is needed to prove the triangles are congruent through AAS?
Answer:
C. <C is congruent to <Y
Step-by-step explanation:
to be AAS the angles need to be next to each other
9 friends are lining up. Joe, Susan, John, and Meredith must be beside each other. How many ways can they line up?
This is one single number slightly over 17 thousand.
You may need to erase the comma when typing the answer in.
=========================================================
Explanation:
Let's say that another person steps in for Joe, Susan, John, and Meredith. I'll refer to this person as the teacher (perhaps these 9 friends are students on a field trip).
The 9 friends drops to 9-4 = 5 people when those four named people leave the group temporarily. Then it bumps up to 5+1 = 6 people when the teacher steps in. Wherever the teacher is located, the four friends that left will replace the teacher. This guarantees that those four friends stick together.
There are 6! = 6*5*4*3*2*1 = 720 ways to arrange those 6 people. The exclamation mark is a factorial symbol.
Within any of those 720 permutations, we have 4! = 4*3*2*1 = 24 ways to arrange those group of named people when they come back to replace the teacher.
So overall the answer is 4!*6! = 24*720 = 17,280
You may need to erase the comma when typing the answer in.
-------------
Side note: There are 9! = 362,880 ways to arrange all nine friends regardless if those four mentioned people stick together or not. We see that they stick together roughly (17,280)/(362,880) = 0.0476 = 4.76% of the time.
Convert 0.53 hectograms to centigrams.
53 centigrams
0.000053 centigrams
530 centigrams
5,3000 centigrams
Answer:
As for metric prefixes, "hecto" means hundred and "centi" means hundredth.
So, converting .53 hectograms to centigrams requires multiplying it by 10,000.
So, .53 hectograms * 10,000 equals 5,300 centigrams.
Source http://www.1728.org/convprfx.htm
Step-by-step explanation:
im stuck on this question!!!!
Answer:
reflected across the y axis: (5,2)
reflected across the x axis: (-2,5)
Answer:
Answer: (5,2) when reflected off the y-axis. (-5,-2) when reflected off the x-axis
Given that Z1 = 1 + i and Z2 = 3 - 4i, find z1z2
Answer:
7-i
Step-by-step explanation:
It is asking for the product of the given complex numbers.
Z1Z2 means Z1 times Z2
(1+i)(3-4i)
You can do the whole foil thing here since we are multiplying a pair of binomials. But all you are doing when you do that is multiplying every term in the first ( ) to every term in the second ( ).
1(3)+1(-4i)+i(3)+i(-4i)
Simplify each term. That is, perform the multiplication in each term:
3-4i+3i-4i^2
Combine like terms and also replace i^2 with (-1):
3-1i-4(-1)
Multiplication identity property used:
3-i+4
Combine like terms:
7-i
An analysis of 99 Wall Street traders showed that 32 of their stock picks beat the market average. What is the estimate of the population proportion
Answer:
The estimate of the population proportion is 0.3232.
Step-by-step explanation:
Estimate of the population proportion:
The estimate is the sample proportion, which is the number of desired outcomes divided by the number of total outcomes.
In this question:
32 out of 99, so:
[tex]p = \frac{32}{99} = 0.3232[/tex]
The estimate of the population proportion is 0.3232.
A walking path across a park is represented by the equation y = -4x + 10. A new path will be built perpendicular to this path. The paths will intersect at the point (4, -6). Identify the equation that represents the new path.
Answer: [tex]y=\frac{1}{4}x-7[/tex]
Step-by-step explanation:
The perpendicular slope of the line(m) = [tex]-\frac{1}{m}[/tex]:
m = -4 ⇒ [tex]-\frac{1}{m} =-\frac{1}{(-4)} =\frac{1}{4}[/tex]The function formula is y = mx + b, where the y-intercept(b) is found by substituting in the values of a point on the line ⇒ (4, -6):
[tex]y=\frac{1}{4}x+b\\-6=\frac{1}{4}(4)+b\\-6=1+b\\b=-6-1=-7[/tex]
So the perpendicular equation is [tex]y=\frac{1}{4}x-7[/tex].
Someone help me please
9514 1404 393
Answer:
A = (0, 1)B = (3, -2)area = 4.5 square unitsStep-by-step explanation:
Rewriting the equations to make x the subject, we have ...
x = y² -1 . . . . . [eq1]
x = 1 - y . . . . . .[eq2]
At the points of intersection, the difference will be zero.
y² -1 -(1 -y) = 0
y² +y -2 = 0
(y -1)(y +2) = 0
The y-coordinates of points A and B are 1 and -2.
The corresponding x-coordinates are ...
x = 1 -{1, -2} = {1 -1, 1+2} = {0, 3}
Then A = (0, 1) and B = (3, -2).
__
A differential of area can be written ...
(x2 -x1)dy = ((1 -y) -(y² -1))dy = (2 -y -y²)dy
Integrating this over the interval y = [-2, 1] gives the area.
[tex]\displaystyle A=\int_{-2}^1(2-y-y^2)\,dy=\left.(2y-\dfrac{1}{2}y^2-\dfrac{1}{3}y^3)\right|_{-2}^1\\\\=\left(2-\dfrac{1}{2}-\dfrac{1}{3}\right)-\left(2(-2)-\dfrac{(-2)^2}{2}-\dfrac{(-2)^3}{3}\right)=\dfrac{7}{6}+4+2-\dfrac{8}{3}\\\\=\boxed{4.5}[/tex]
The area of the shaded region is 4.5 square units.
What is the area of 4cm×7cm×8cm
Answer:
[tex]224cm^3\\[/tex]
Step-by-step explanation:
[tex]4cm*7cm*8cm=[/tex]
[tex]=224cm^3[/tex]
Hope this is helpful.
LWH=A
Plug in the numbers:
4*7*8=224^2
The area would be 224cm^2.
Write 2 1/4 as a decimal
Hey there!
2 1/4
= 2 * 4 + 1 / 4
= 8 + 1 / 4
= 9 / 4
= 9 ÷ 4
= 2.25
Therefore, your answer is: 2.25
Good luck on your assignment & enjoy your day!
~Amphitrite1040:)
What are the coordinates of point p?
I need help with this question.
Answer:
Step-by-step explanation:
f(x-2) means that x is happening sooner or a shift to the left and
+4 means that the whole function moves up 4.
The 1st choice looks good
What is the depth of water in a tank with 300,000 gallons of water at 70F when the pressure gauge at the bottom of the tank reads 23 psig?
Answer:
53.08 ft
Step-by-step explanation:
The pressure at the bottom of the tank, P = ρgh where ρ = density of water = 1000 kg/m³, g = acceleration due to gravity = 9.8 m/s² and h = depth of water in tank.
Since the pressure at the bottom of the tank, P = ρgh, making h subject of the formula, we have
h = P/ρg
Since P = 23 psig = 23 × 1 psig = 23 × 6894.76 Pa = 158579.48 Pa
Substituting the values of the other variables into h, we have
h = P/ρg
h = 158579.48 Pa/(1000 kg/m³ × 9.8 m/s²)
h = 158579.48 Pa/(9800 kg/m²s²)
h = 16.18 m
h = 16.18 × 1 m
h = 16.18 × 3.28 ft
h = 53.08 ft
The equation for the pH of a substance is pH = -log[H], where Ht iS the concentration of hydrogen ions. A basic
solution has a pH of 11.2. An acidic solution has a pH of 2.4. What is the approximate difference in the concentration
of hydrogen ions between the two solutions?
Answer:
The difference in the H⁺ concentration between the two solutions is approximately equal to the H⁺ concentration of the acidic solution.
Step-by-step explanation:
The pH is given by:
[tex] pH = -log[H^{+}] [/tex]
Where:
[tex] [H^{+}][/tex]: is the concentration of hydrogen ions.
For the basic solution (pH = 11.2), the concentration of H⁺ is given by:
[tex] [H^{+}]_{b} = 10^{-pH} = 10^{-11.2} = 6.31 \cdot 10^{-12} [/tex]
And, for the acidic solution (pH = 2.4) we have:
[tex] [H^{+}]_{a} = 10^{-pH} = 10^{-2.4} = 3.98 \cdot 10^{-3} [/tex]
Hence, the difference in the concentration of H⁺ between the two solutions is:
[tex] \Delta H^{+} = [H^{+}]_{a} - [H^{+}]_{b} = 3.98 \cdot 10^{-3} - 6.31\cdot 10^{-12} = 3.98 \cdot 10^{-3} [/tex]
Therefore, the difference in the H⁺ concentration between the two solutions is approximately equal to the H⁺ concentration of the acidic solution.
I hope it helps you!
Answer:
B. 4.0 x [tex]10^{-3}[/tex]
Step-by-step explanation:
EDG2021
An office manager buys 2 office chairs and 4 file cabinets for $380. Next year she buys 4 office chairs and 6 file cabinets for $660. What is the cost of each office chair, c? What is the cost of each file cabinet, f? Explain how you fond the cost of each chair and file cabinet.
Answer:
16.5
Step-by-step explanation:
Answer:
file cabinet = 50
chair = 90
Step-by-step explanation:
x = chair
y = file cabinet
1st year, solve for x
2x+4y = 380
2x = 380 - 4y
x = 190 - 2y
2nd year
Now substitute x = 190 - 2y in your 2nd year formula
4x+6y = 660
4(190-2y)+6y = 660
760 - 8y + 6y = 660
-2y = -100
y = 50
The cost of the filling cabinet is 50 each
Now use the value for y (50) in your first formula to get x
2x+4y=380
2x+4*50=380
2x=380-200
2x=180
x=90
Please kindly help
According to a newspaper article 15% more home remodeling was done in 1985 than in 1984. Professionals performed 75% of all remodeling. If $80.4 billion was spent on residential remodeling in 1985 what was the value of the work done by professionals in 1985?
(1) $ 8.4 billion
(2) $12.06 billion
(3) $20.1 billion
(4) $60 billion
(5) $60.3 billion
Answer:
(3) $20.1 billion
Step-by-step explanation:
hope it help
Answer:
(5) $60.3 billion
Step-by-step explanation:
(10 points!) The function below has an input, x, and produces a specific output, c. (Pictured below.)
Answer:
x =[tex]x =(\frac{c}{4} )^{1/3} \\[/tex]
input 2 output 32
output 256 input 4
Step-by-step explanation:
rationalize the denominator of √3+√2\ 5+√2
Answer:
[tex]\frac{ 5 \sqrt3 \ + \ 5 \sqrt2 \ - \ \sqrt6 \ - \ 2}{23}[/tex]
Step-by-step explanation:
[tex]\frac{\sqrt3 \ + \ \sqrt2 }{5 \ + \ \sqrt2 } \\\\=\frac{\sqrt3 \ + \ \sqrt2 }{5 \ + \ \sqrt2 } \times \frac{5 \ - \ \sqrt2 }{5 \ - \ \sqrt2 } \\\\=\frac{( \sqrt3 \ + \ \sqrt2)(5 \ - \ \sqrt2)}{(5 \ + \ \sqrt2)( 5 \ - \ \sqrt 2 )}\\\\=\frac{( \sqrt3 \ + \ \sqrt2)(5 \ - \ \sqrt2)}{(5 \ + \ \sqrt2)( 5 \ - \ \sqrt 2 )}\\\\=\frac{5 \sqrt3 \ + \ 5\sqrt 2 \ - \ \sqrt{ 3\times 2 } \ - \ \sqrt{2 \times 2}}{(5)^2 \ - \ (\sqrt2)^2}\\\\= \frac{ 5 \sqrt3 \ + \ 5 \sqrt2 \ - \ \sqrt6 \ - \ 2}{25 - 2}\\\\[/tex]
[tex]= \frac{ 5 \sqrt3 \ + \ 5 \sqrt2 \ - \ \sqrt6 \ - \ 2}{23}[/tex]
What is the following product? Assume d>0 3vd•3vd•3vd
Answer:
A. d
Step-by-step explanation:
If you find the 3rd square root or whatever its called, and multiply it by itself again 3 times, You end up with d again.
What is the midpoint of AB?
Answer:
point G
Step-by-step explanation:
There's 14 marks between point A and B(counting point B). 14/2=7, the 7th mark is point G.
PLEASE HELP!!! WILL GIVE BRAINLIEST!!!!
Finding the line of best fit is something a Machine Learning Model would do.
This particular ML model is called "Linear Regressor" or "Linear Regression Model". Look it up and there are definitely calculators for it, as it is relatively simple.
You can also, if you know how to use ML libraries and code, use Python to determine the value of [tex]b[/tex].
Hope this helps.
The height and base radius of a cone are increased by a factor of 2 to create a similar cone. How is the slant height of the cone affected? The slant height of the larger cone is equal to the slant height of the smaller cone. The slant height of the larger cone is double the slant height of the smaller cone. The slant height of the larger cone is 4 times the slant height of the smaller cone. The slant height of the larger cone is 8 times the slant height of the smaller cone.
Answer:
The slant height of the cone affected is two times the slant height of original cone
Step-by-step explanation:
we know that
If the height and base radius of a cone are increased by a factor of to create a similar cone
then
the scale factor is equal to
therefore
the slant height of the cone affected is equal to the slant height of the original cone multiplied by the scale factor
Find the slant height of the original cone
Let
l-----> slant height of original cone
la-----> slant height of the cone affected
Applying the Pythagoras theorem
so
The slant height of the cone affected is two times the slant height of original cone
(I GOT THIS FROM SOMEONE ELSES ANSWER IN 2017 SO I HOPE THIS HELPS)
The slant height of the larger cone is double the slant height of the smaller cone.
Option B is the correct answer.
What is a cone?It is a shape of a Christmas tree where there is a base of radius r and a top point called the apex.
The volume of a cone is 1/3 πr²h
We have,
The slant height of the cone is affected by a factor of 2.
When the height and base radius of a cone are multiplied by 2, the dimensions of the new cone are doubled.
Therefore,
The slant height of the larger cone is double the slant height of the smaller cone.
Learn more about cones here:
https://brainly.com/question/13798146
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