The sum of the first ten terms of an arithmetic progression consisting of

positive integer terms is equal to the sum of the 20th, 21st and 22nd term.

If the first term is less than 20, find how many terms are required to give

a sum of 960.

Answers

Answer 1

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 2

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


Related Questions

find x and y on triangle
Also the degree is 30 and the other thing is 7sqrt3​

Answers

Answer:

y =7

x =14

Step-by-step explanation:

Since this is a right triangle we can use trig functions

tan 30 = opp /adj

tan 30 = y/ 7 sqrt(3)

7 sqrt(3)  tan 30 = y

7 sqrt(3) * 1/ sqrt(3) =t

7 =y

sin 30 = opp/ hyp

sin 30 = 7/x

x sin 30 =7

x = 7/ sin 30

x = 7 / 1/2

x = 14

Workbook
WB-21
38. What is the circumference of a circle that has a diameter of 12 inches? (Use
3.14 for 1.)
a. 15.14 inches
b. 37.68 inches
c. 376.8 inches
d. 9.42 inches
HUN
39. A ski resort reported 53.9 inches of snow in November, 73.75 inches of
snow in December and 95.8 inches of snow in January. What is the average
amount of snow that fell for the three months?
a. 80 inches
b. 223.15 inches
c. 74 inches
d. 74.48 inches
40. Dan is building a deck. He has a board 5 1/2 feet long and another
board 7 feet long. How many 1 1/2-foot boards can he cut from the
7-foot board?
a.
5
b. 3
c. 5 1/2
d. 1

Answers

Answer:

1=circum=37.7inc&diam=7 inc

The answer to your question is 7inches

what is the length of GN, given that figure LMNO is a square PLZ HELP!!!!!

Answers

Answer:

A. 4

Step-by-step explanation:

The diagonals are also congruent to each other. Diagonals of a square bisect each other. This implies that:

MO bisects LN, thereby dividing LN into two equal segments, LG and GN.

Thus, LG = GN.

Since the length of LG = 4, therefore:

GN = 4

700,000 rounded to the nearest hundred thousand

Answers

Answer:

700,000

Step-by-step explanation:

700,000 is already a 100,000, therefore there is no rounding to do.

Answer:

700,000 is the answer

Step-by-step explanation:

TRSU is a rhombus. Find SU.

Answers

Answer:

SU = 1

Step-by-step explanation:

First because all sides are equal set the two sides equal to each and solve for x

2x + 5 = 5x + 2

Isolate the x-terms

2x + 5 - 2 - 2x = 5x + 2 - 2 - 2x

5 - 2 = 5x - 2x

3 = 3x

Divide both sides by 3

x = 1

Answer:

it’s 7

Step-by-step explanation:

Find the greatest number of students to whom 45 soccer balls and 60 tennis balls can be equally divided.

Answers

Answer:

15 students

Step-by-step explanation:

Find GCF of 45 and 60:

45 = 3*3*560 = 2*2*3*5

GCF(45,60) = 3*5 = 15

Soccer balls=45Tennis balls=60

Find Greatest common multiple or GCF

[tex]\\ \sf\longmapsto 45=3\times 3\times 5[/tex]

[tex]\\ \sf\longmapsto 60=2\times 2\times 3\times 5[/tex]

Now

[tex]\\ \sf\longmapsto GCF=3\times 5=15[/tex]

a company has decreased the weight of its boxes of macaroni by 8 %. if the new weight of the box is 13.1ounces, what was the original weight of the​ box?

Answers

Answer:

실례합니다 ?

Step-by-step explanation:

이것이 무엇을 의미하는 질문입니까?

회사는 마카로니 상자의 무게를 8% 줄였습니다. 상자의 새 무게가 13.1온스인 경우 상자의 원래 무게는 얼마였습니까? 오른쪽 ?

Answer:

x*0.92 = 13.1

x = 14.24

Step-by-step explanation:

Complete the function table.
Input (n) Output (n-2)

Answers

Answer:  Choice C

This is because the input n = 2 leads to the output n-2 = 2-2 = 0

As another example: the input n = 4 leads to the output n-2 = 4-2 = 2

Whatever the input is, subtract 2 from it to get the output.

3/4 + 20 (2/5 x 4/7) ​

Answers

Answer:

i believe the answer is 5.3

A football team has a probability of 0.76 of winning when playing any of the other four teams in its conference. If the games are independent, what is the probability the team wins all its conference games

Answers

Answer:

0.33362176

Step-by-step explanation:

Probability is the ratio of the number of possible outcomes to the number of total outcomes.

Given that a football team has a probability of 0.76 of winning when playing any of the other four teams in its conference, the probability that the team wins all its conference games

= 0.76 * 0.76 * 0.76 * 0.76

= 0.33362176

This is the probability that the teams wins the 4 matches played against the other teams in the conference.

A study is conducted to examine the correlation between Training Time and the Error Rate of employees. If the correlation coefficient of Training Time and Error Rate is -0.76, what is your conclusion?
(The answer is NOT B) HELP Please!!
A Moderate positive correlation
B Strong negative correlation
C No conclusion possible
D No correlation is shown
E Strong positive correlation

Answers

Answer:

No conclusion possible

✓ 1 N 3 4 5 6 Conv A rectangular field is 300 meters long and 250 meters wide. What is the area of the field in square kilometers? Do not round your answer. 1000 millimet 100 centimet 10 decimet 1 decame 2 km Х X 5. ? 1 hectomei 1 ​

Answers

Answer:

75 km

Step-by-step explanation:

Area = Length × Width

= 300m and 250m

= 75000m

M to Km => ÷1000

= 75000m ÷ 1000

= 75 km #

It can be shown that the line with intercepts (a, 0) and (0, b) has the following equation:
x/a + y/b= 1, a ≠ 0, b ≠ 0.

Use this result to write an equation of the line.

Point on line:

(−2, 4)

x-intercept: (a, 0)

y-intercept: (0, a)

(a ≠ 0)

Answers

The equation of the straight line is [tex]x+y=2[/tex].

Given:

The line with intercepts (a,0) and (0,b) has the equation [tex]\frac{x}{a} +\frac{y}{b} =1, a\neq 0, b\neq 0[/tex] Point on the line: (-2, 4)x-intercept: (a, 0)y-intercept: (0, a)[tex]a\neq 0[/tex]

To find: The equation of this line

It is given that a line with intercepts (a,0) and (0,b) has the equation [tex]\frac{x}{a} +\frac{y}{b} =1, a\neq 0, b\neq 0[/tex]

Now, it is given that the referred line has intercepts (a, 0) and (0, a). Then, using the above statement, the equation of this line can be written as,

[tex]\frac{x}{a} +\frac{y}{a}=1[/tex]. It is already given that [tex]a\neq 0[/tex]. So, we need not mention it again.

It is also given that the point (-2, 4) lies on this line. Then, the coordinates of this point must satisfy the equation of the line.

This implies that,

[tex]\frac{-2}{a} +\frac{4}{a} =1[/tex]

[tex]\frac{2}{a} =1[/tex]

[tex]a=2[/tex]

Now, put [tex]a=2[/tex] in the equation of the line, [tex]\frac{x}{a} +\frac{y}{a}=1[/tex] to get,

[tex]\frac{x}{2} +\frac{y}{2} =1[/tex]

[tex]x+y=2[/tex]

So, the equation of the line is [tex]x+y=2[/tex].

Learn more about equations of straight lines here:

https://brainly.com/question/18879008

A research report claims that 20% of all individuals use Firefox to browse the web. A software company is trying to determine if the proportion of their users who use Firefox is significantly different from 0.2. In a sample of 200 of their users, 26 users stated that they used Firefox.

Required:
Using this data, conduct the appropriate hypothesis test using a 0.01 level of significance.

Answers

Answer:

Reject H0

Step-by-step explanation:

Z  = -2.474873734

 

survey (positive) 26

n (total) 200

p 0.2

 

p /point est. 0.13

POPULATION(min) 4000

np        >= 5 ? YES 40

n(1-p)  >= 5 ? YES 160

Sample is valid  

Confidence Level - "P" values  

99% 2.58

Confidence Interval - "P" values  

(0.0686 , 0.1914 )  

Reference=0.2 Reject H0

Which shows the image of rectangle ABCD after the rotation () (W)?
13
VA
1
V

Answers

Answer:

Graph (1)

Step-by-step explanation:

Given rule for the rotation of a figure is,

A(x, y) → A'(-y, x)

This rule defines the rotation of point A by 90° counterclockwise about the origin.

Coordinates of point A → (-2, 0)

Coordinates of point C → (-1, 0)

Following the rule of rotation,

A(x, y) → A'(-y, x)

A(-2, 0) → A'(0, -2)

C(-1, 4) → C'(-4, -1)

Now search the image points from the graphs attached,

Graph (1) will be the answer.

Please help!!
A) In a movie, a mad scientist enlarges a cow to 100 times its normal size. How much stronger would its legs be than a normal cow?
B) How many times more would it weigh than a normal cow?
C) Can you see how results A and B would yield a cow that would collapse under its own weight?

Answers

Answer:

100 times everything.

Step-by-step explanation:

If the cow is 100 times larger than its normal size, obviously everything else should be 100 times stronger and heavier.

SOVE, REDUCE TO LOWEST TEERMS SIMPLIFY IMPROPER FRACTIONSAS MIXED FRACTIONS

Answers

I don’t see a picture

12 workers take 4 hours to complete a job. How long would it take 15 workers to complete the job?

Answers

Answer:

3.75

Step-by-step explanation:

I WILL GIVE BRAINLEST FAST PLEASE ANSWER THE QUESTION IN THE IMAGE

Answers

Answer:

Cannot be determined

Step-by-step explanation:

We only know one angle and we could only compare one set of sides.

We do not have enough information to determine if the triangles are similar

Answer: D. Cannot be determined

88%
19. What is the solution X in this equation? 2(3x - 7) + 4(3x + 2) = 6(5x+9) + 3

Answers

[tex]\\ \sf\longmapsto 2(3x-7)+4(3x+2)=6(5x+9)+3[/tex]

[tex]\\ \sf\longmapsto 6x-14+12x+8=30x+54+3[/tex]

[tex]\\ \sf\longmapsto 6x+12x-14+8=30x+57[/tex]

[tex]\\ \sf\longmapsto 18x+6=30x+57[/tex]

[tex]\\ \sf\longmapsto 30x-18x=6-57[/tex]

[tex]\\ \sf\longmapsto 12x=51[/tex]

[tex]\\ \sf\longmapsto x=\dfrac{51}{12}[/tex]

A building 51 feet tall casts a shadow 48 feet long. Simultaneously, a nearby statue casts a shadow of 16 feet. How tall is the statue? Choose an answer

Answers

Answer: 17 feet

Step-by-step explanation:

51/48 = x/16

(51)(16)/48

The statute is 17 feet tall.

What are the similar triangles?

Similar triangles are the triangles that have the same shape, but different sizes. The corresponding angles are congruent and the sides are in proportion.

What is the ratio of any two corresponding sides of similar triangles?

The ratio of any corresponding sides in two equiangular triangles is always the same.

Let's visualize the situation according to the given question.

AB is the building ,whose height is 51f

BC is the shadow of the building AB, whose length is 48ft.

QR is the shadow of the tower statue, whose length is 16feet.

Let the height of the statue PR be h feet.

In triangle ACB and triangle PRQ

∠ACB = ∠PRQ = 90 degrees  

( the objects and shadows are perpendicular to each other)

∠BAC = ∠QPR

( sunray falls on the pole and tower at the same angle, at the same time )

ΔACB similar to ΔPRQ   ( AA criterion)

Therefore, the ratio of any two corresponding sides in equiangular triangles is always same.

⇒ AC/CB = PR/RQ

⇒[tex]\frac{51}{48} =\frac{h}{16}[/tex]

⇒ h = [tex]\frac{(51)(16)}{48}[/tex]

⇒ h = 17 feet.

Hence, the statute is 17 feet tall.    

Learn more about the similar triangle here:

brainly.com/question/25882965

#SPJ2

Which of the following represents the factorization of the trinomial below?
- 4x3 - 4x2 +24 x
O A. -4(x2-2)(x+3)
B. -4(x2 + 2)(x+3)
O C. -4x(x + 2)(x+3)
D. -4x(x - 2)(x+3)

Answers

Answer:

D. -4x(x - 2)(x+3)

Step-by-step explanation:

We are given the following trinomial:

[tex]-4x^3 - 4x^2 + 24x[/tex]

-4x is the common term, so:

[tex]-4x(\frac{-4x^3}{-4x} - \frac{4x^2}{-4x^3} + \frac{24x}{-4x}) = -4x(x^2+x-6)[/tex]

The second degree polynomial can also be factored, finding it's roots.

Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

[tex]ax^{2} + bx + c, a\neq0[/tex].

This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:

[tex]x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}[/tex]

[tex]x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}[/tex]

[tex]\Delta = b^{2} - 4ac[/tex]

x² + x - 6

Quadratic equation with [tex]a = 1, b = 1, c = -6[/tex]

So

[tex]\Delta = 1^{2} - 4(1)(-6) = 25[/tex]

[tex]x_{1} = \frac{-1 + \sqrt{25}}{2} = 2[/tex]

[tex]x_{2} = \frac{-1 - \sqrt{25}}{2} = -3[/tex]

So

[tex]x^2 + x - 6 = (x - 2)(x - (-3)) = (x - 2)(x + 3)[/tex]

The complete factorization is:

[tex]-4x(x^2+x-6) = -4x(x - 2)(x + 3)[/tex]

Thus the correct answer is given by option d.

write your answer in simplest radical form​

Answers

9514 1404 393

Answer:

  4√2

Step-by-step explanation:

In a 30°-60°-90° triangle, the ratio of side lengths is ...

  1 : √3 : 2

That is, the hypotenuse (c) is double the short side (2√2).

  c = 4√2

Calculate 50% of 7.9 giving your answer to one decimal place?

Answers

Answer:

4.0

Step-by-step explanation:

50% means half.

Divide by 2.

7.9 ÷ 2 = 3.95.

Round to the tenths place.

4.0

I hope this helps!

pls ❤ and mark brainliest pls!

Is -1 rational or irrational

and is √3 + -1 Rational or irrational

explain if u can pls​

Answers

Answer:

-1: rational

√3 + -1: irration

Step-by-step explanation:

A rational number is negative, if its numerator and denominator are of the opposite signs.

Hope this helps <3

Kara ate 2 7/9 of the raisins she packed. Which box shows the decimal equivalent of the amount of raisins she ate? Box A: 2.777 etc Box B: 2.79 Box C: 2.999 etc.

Answers

Answer:  Box A, 2.777

=======================================================

Explanation:

When using a calculator or long division, you should find that

7/9 = 0.7777...

where the 7s go on forever

So we can say that 7/9 = 0.777 approximately. You could argue that the last '7' would round up to an '8' and we could say 7/9 = 0.778; however, I'll stick to the first value so that it matches with the answer.

Since 7/9 = 0.777, this means 2 & 7/9 = 2 + 7/9 = 2 + 0.777 = 2.777 which is box A.

Answer:

A

Step-by-step explanation:

What is the median to 17,19, 20, 21, 22, 25, 29, 30, 32, 35

Answers

Answer:

23.5

Step-by-step explanation:

The median is the middle value when the numbers are put in order from smallest to largest

17,19, 20, 21, 22, 25, 29, 30, 32, 35

There are 10 numbers

17,19, 20, 21, 22,      25, 29, 30, 32, 35

The middle is between 22 and 25

(22+25)/2 = 47/2 =23.5

Which Expression is equivalent to -2(x + 6) 2x + (-12) 2x + 12 2x + 6​

Answers

Answer:

-2x -8

Step-by-step explanation:

Find the distance between (6,6) & (-6,2)
Round your answer to the nearest 100th

Answers

Answer:

65

Step-by-step explanation:

show your work and practic

Find y when x = 4 (30 points)

Answers

Answer:

y = 54/25

Step-by-step explanation:

y = p×q^(x-1)

when x = 1 then y = 10

so,

10 = p×q^(1-1)

or, 10 = p×1

or, p = 10

when x = 6 then y = 0.7776

0.7776=p×q^(6-1)

or, 0.7776=p×q^5

or, 0.7776=10×q⁵

[0.7776 = 7776/10000 = 486/625]

or, 486/625 = 10×q⁵

or, 486/6250=q⁵

or, [tex] \frac{ \sqrt[5]{486} }{ \sqrt[5]{6250} } = q[/tex]

or, [tex]q = \frac{3 \sqrt[5]{2} }{5 \sqrt[5]{2} } [/tex]

or, q = 3/5

so, when x = 4

y = p×q^(x-1)

y = 10×(3/5)^(4-1)

y = 10×(3/5)^3

y = 10×27/125

y = 54/25

Other Questions
On January 1, 2016, Tessa loaned $12,000 to another company on a three-year, 4% note. No interest was accrued in 2016. Cash will not be received for the interest until the end of the three-year period. The error was discovered before adjusting and closing entries were posted on December 31, 2017. Ignoring income taxes, what should be the correct journal entry on December 31 How do you feel about yourself as a responsive citizen ? Underline the pronouns in each of following sentences What is 3x^2-5x-13=0 To compare the teaching methodologies of two of its eighth-grade math teachers, a school decides to compare student test scores from the two classes throughout the year.Which type of statistical study is the school conducting?a) Matched-pair design studyb) Meta-analysisc) Retrospective observational studyd) Prospective observational study how would you detect sulphur in organic compounds write 10 multiple choice questions where you ask 3 respondents 10 questions about teenage pregnancy The perimeter of a rectangle is given by the formula P=2w+2l,where w is the width and l is the length.Rearrange the formula for the length ( ). Comment s'appelle la tendance qui prconise l'inspiration plurielle Katie, Merci de bien vouloir fermer mon compte, puisque je suis un voyou qui ne respecte pas le code thique Two sides of a right triangle measure 5 inches and 6 nches, and the third side measures 61 inches.The length of the third side is about inches _ . The perimeter of the triangle is about inches. __ SOMEONE HELL FAST ILL GIVE U BRAINLIST!!! Find the value of each expression.30 3 2 A solution is made by mixing 34.5 g of sugar with 75.0 g of water. What is the mass percent of sugar in this solution? Please explain and show work. Please help thx and I will mark you as brainliest! U (24 win Q7 A gardener needs to order fertiliser for a piece of land. The piece of land is a square with sides measuring 8 metres. This formula shows how many grams of fertiliser she needs. grams of fertiliser needed = length in metres x width in metres x 25 The supplier sells these bags of fertiliser. 10K 5kg 2kg 1kg 1 kilogram 2 kilograms 5 kilograms 10 kilograms Which bag of fertiliser should the gardener order? Include figures to explain your answer. Show all your working. What is indirect program memory addressing? Explain the working of the following instructions? a) JMP AXb) JMP LIST[DX]c) JMP NEAR PTR[DI+3] mAFD=90 . mAFB=31. Find mDFE.A. 87B. 29.5C. 31D. 28 Classify the following polynomials according to the number of terms. Combine any like terms first. Help question 25 pleasee