4. Find the sum of all the numbers from 100 to 199 that are not divisible by 13.
What is the formula for
this?

Answers

Answer 1

There are 100 numbers in the range 100-199. Find the smallest and largest multiple of 13 in this range. We have

104 = 8•13

195 = 15•13

so there are 15 - 8 + 1 = 8 multiples of 13 between 100 and 199.

Then the sum we want is

[tex]\displaystyle \sum_{k=100}^{199} k - \sum_{\ell=8}^{15}13\ell[/tex]

or equivalently,

(100 + 101 + 102 + … + 199) - 13 (8 + 9 + … + 15)

To compute these sums, recall the following formula:

[tex]\displaystyle \sum_{i=1}^n i = 1 + 2 + 3 + \cdots + n = \frac{n(n+1)}2[/tex]

Then

[tex]\displaystyle \sum_{k=100}^{199} k = \sum_{k=1}^{199} k - \sum_{k=1}^{99} k = \frac{199\cdot200}2 - \frac{99\cdot100}2 = 14,950[/tex]

and

[tex]\displaystyle \sum_{\ell=8}^{15} 13\ell = 13 \left(\sum_{\ell=1}^{15} \ell - \sum_{\ell=1}^7 \ell\right) = 13 \left(\frac{15\cdot16}2 - \frac{7\cdot8}2\right) = 1,196[/tex]

which means the sum we want is 14,950 - 1,196 = 13,754.


Related Questions

Soraya earned $40 in October. She earned $50 in
November.
What is the percent increase or decrease in Soraya's monthly earnings?
A. 15% decrease
B. 30% increase
C. 25% increase
D. 20% decrease

Answers

25% increase.

Explanation: 25% of $40 is $10. You add $10 to $40 you get $50.

Solve the equation: 3.017 + k = 5.134

Answers

Answer:

k=2.117

Step-by-step explanation:

Answer:

3.017 + k = 5.134

So, k = 5.134 - 3.017

So, k = 2.117

The length of a rectangle is three times its width. if the area of the rectangle is 75 in2, find its perimeter.

Answers

Answer:

  40 in

Step-by-step explanation:

For a width of w, the length is 3w and the area and perimeter are ...

  A = LW = (3w)(w) = 3w^2

  P = 2(L+W) = 2(3w +w) = 8w

We are given the area, so we can find w to be ...

  75 in^2 = 3w^2

  25 in^2 = w^2 . . . . . divide by 3

  5 in = w . . . . . . . . . square root

Then the perimeter is ...

  P = 8w = 8(5 in) = 40 in

Last year at a certain high school, there were 100 boys on the honor roll and 60 girls on the honor roll. This year, the number of boys on the honor roll decreased by 11% and the number of girls on the honor roll decreased by 10%. By what percentage did the total number of students on the honor roll increase? Round your answer to the nearest tenth (if necessary).​

Answers

Answer:

-11 boys -6 girls

Step-by-step explanation:

a man walks for 45 minutes at a rate of 3 mi/h then jogs for 75 minutes at a rate of 5 mi/h then rests for 30 minutes and finally walks for 90 minutes at a rate of 3 mi/h. Write a piecewise-defined function expressing the distance he traveled as a function of time.

Answers

Answer:

Sorry need points

Step-by-step explanation:

the odds against your bet are to 3. if you bet $27 and win. how much you win​

Answers

If you win, you will get eighty-one dollars ($81.00)
If you win you will get $81 because 3*27= 81

geomtry plz help 15 points

Answers

Answer:

it should be 60°. the single marks on each side means they are all equal

Answer:

m∠L=60º

Step-by-step explanation:

The triangle is an equilateral triangle meaning that all angles and sides are equal.

m∠L=60º

Hope this helps :)

A punch recipe requires 2 cups of cranberry juice to make 4 gallons of punch. Using the same recipe, what is the amount of cranberry juice needed for 12 gallon of punch

Answers

Answer:

we need 6 cups of cranberry juice for 12 gallons of punch

Suppose `h\left(t\right)=-5t^{2}+10t+3`is an expression giving the height of a diver above the water (in meters), t seconds after the diver leaves the springboard.



a. How high above the water is the springboard? Explain how you know.

Answers

Answer:

Step-by-step explanation:

a) The height of the springboard above the water should be h(0) : Read, the height at t = 0

h(0) = -5(0) + 10(0) + 3

h(0) = 0 + 0 + 3

h(0) = 3

a) 3 meters

b)  The time it takes the diver to hit water should be, the positive 0 solution for t.  Remember, in a quadratic equation,  there are two values for t where a parabola crosses the horizontal axis, which in this case would be t.  Just by looking at the function, h(t) = -5t2 + 10t + 3 , one should be able to see that it cannot be factored easily, so it requires the Quadratic Formula to find the zeros ; x = -b ±√(b2-4ac)  / 2a

Substitute t for x, and use the coefficients for a, b, c:

t  =  (-10 ± √((102 - 4(-5)(3)))/2(-5)

t = (-10 ±√(100 + 60))/-10

t = (-10 ±√160)/-10) ; Now factor the 160 to simplify:

t = (-10 ±√(10*16))/-10

t = (-10 ±4√10)/-10 ; Factor out leading coefficient of -2 from the numerator:

t = -2(5 ± 2√10)/-10

t = (5 ± 2√10)/5

Using a calculator to find the zeros, and disregarding the negative zero (because t starts at 0):

t ≈ 2.265

b) approx. 2.265 seconds for diver to hit water.

c) To find this, set the function equal to 3 to find what other value for t would be equal to 3 (we know one is 0).

-5tt + 10t + 3 = 3

-5t2 + 10t = 0 ; factor out t

t(-5t + 10) = 0

We know t = 0:

We also know that -5t + 10 = 0

-5t = -10

t = 2

c) 2 seconds. This is the time that diver would equal height of t=0 which is where he started, and where he equals the height of the springboard.

d and e) The peak of the dive (parabola), is determined using the formula h = -b/2a (Derived from the Quadratic Formula) to find the y value (in this case, the h value, answering e) and then using that result in the function to find the x value (in this case, the t value answering d) of the point where the parabola (dive path) reaches a maximum(height), or minimum(in upward opening parabolas).

h = -10/2(-5)

h = -10/-10

h = 1

h(1) = -5(1)2 + 10(1) + 3

h(1) = -5 + 10 + 3

h(1) = 8

d) At t = 1 second, diver will have reached peak of dive.

e) At t = 1 second, diver will have reached a maximum height of 8 meters.

Find the domain of the function.



f(x) = -5x + 3

Answers

Enter a problem...

Calculus Examples

Popular Problems Calculus Find the Domain and Range f(x)=5x-3

f

(

x

)

=

5

x

3

The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.

Interval Notation:

(

,

)

Set-Builder Notation:

{

x

|

x

R

}

The range is the set of all valid

y

values. Use the graph to find the range.

Interval Notation:

(

,

)

Set-Builder Notation:

{

y

|

y

R

}

Determine the domain and range.

Domain:

(

,

)

,

{

x

|

x

R

}

Range:

(

,

)

,

{

y

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}

e/kaid_274404147475337871026587/assig!
Khan Academy
Percent word problems
Of the 50 U.S. states, 4 have names that start with the letter W.
What percentage of U.S. states have names that start with the letter W?
0
Stuck? Review related articles/videos or use a hint.

Answers

Answer:

Step-by-step explanation:

4/50 = 0.08

0.08(100) = 8%

Given the following exponential function, identify whether the change represents growth or decay, and determine the percentage rate of increase or decrease.
y=21(0.97)^x
what is the % increase

Answers

Answer:

Step-by-step explanation:

As the number under the exponent is less than 1, this is a decay function.

y decreases by (1 - 0.97)100 = 3% for each unit increase in x

so the increase would be -3%

Show this situation on a vertical number line

Answers

what is the situation to your question

Answer:

What is the situation?

Step-by-step explanation:

Expand the function.
f(x) = (2x + 3)4

Answers

Answer:

y = 8x + 12

Step-by-step explanation:

y = (2x + 3)4

Distribute the 4 to the 2x  and 3

y = 8x + 12

^ Expanded form

Please take a look at the picture

Answers

[tex]\implies {\blue {\boxed {\boxed {\purple {\sf {C.\:None\:of\:the\:above.}}}}}}[/tex] ✔

[tex]\:\large{\boxed{\frak{ Step-by-step\:explanation: }}}[/tex]

A. [tex]x - ( - x) = -x[/tex]

Let us first solve for L. H. S.

We have,

[tex]x - ( - x)[/tex]

[tex] = x + x[/tex]

[tex] = 2x[/tex]

[tex]≠ - x[/tex]

[tex]≠ R. H. S. [/tex]

Hence, option A is incorrect.

B. [tex]0 - ( - x) = - x[/tex]

Solving for L.H.S. , we have

[tex] = 0 - ( - x)[/tex]

[tex] = + x[/tex]

[tex]≠ - x[/tex]

[tex]≠ R. H. S. [/tex]

Hence, option B is ruled out too.

Therefore, the correct answer is [tex]\sf\red{ option\:C}[/tex].

please help me calculation completing square?
x²+2x-24=0?​

Answers

Answer:

x = 4, -6

Step-by-step explanation:

x = 4, -6

g A long-term study has revealed that a test for cancer in men is very effective. The study shows that 89% of the men for which the test is positive actually have cancer. If a man selected at random tests positive for cancer with this test, what is the probability that he does not have cancer

Answers

The answer is 89% because I had that Same question and it was 89%

help me please the drop down menu is the same for top and bottom i’m lost:(

Answers

I think…

0=2 : no solutions
2=2 : infinite solutions

Answer:

1) No solution

2) Infinitely many solutions

Step-by-step explanation:

1) No solution

0=2 is false.

2) Infinitely many solutions

2=2 is true because both sides are equal, hence, it is an infinite solution.

Hope this helps :)

What is 11% of 96 students

Answers

Answer:

8.7

Step-by-step explanation:

8.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.78.7

2x - 5y = 6 and -2x + 7y = 14

*Using elimination*​

Answers

2x-5y+ (-2x) + 7y= 6+14
2y = 20
y= 10
2x-5(10)=6
2x= 56
x= 28
here is the ans.hope this helps!

What are 5 rules to follow in a science lab?

Answers

Answer:

Step-by-step explanation:

1. Wear safety glasses

2. Be accompanied by an adult

3. Wear proper lab clothing

4. Alert Lab instructor if an accident were to happen

5. Follow all instructions given by lab instructor

solve pls brainliest

Answers

5.15, 5.2222, 5.19, 5.169



1: 103/20 2: 5.169 3: 5.19 4: 5 2/9

We have: 103/20= 5,15   ;   5 2/9= 5,(2)

So the answer is:

103/20 < 5.169 < 5.19 < 5 1/2

ok done. Thank to me :>

if a chocolate cake is divided into six equal slices and each slice has 280 calories

Answers

Answer:

Whats the question?

Step-by-step explanation:

Answer:

1,680

Step-by-step explanation

6 slices each 280 calories, 280 x 6 = 1,680

plz help on a timed test will pay 10 points and make brainlest

What other countries have set up early earthquake warning systems? Which of these countries are in the Ring of Fire? Why is it important for these Ring of Fire countries to have warning systems?

Answers

Answer:

Mexico, Japan, South Korea, Taiwan, and the United States, Chile, Japan, the US west coast;  Chile, Japan, the US west coast; So all that is left for the people who live around the Ring of Fire is to be aware of the danger, perhaps to live further inland, build safer, earthquake-resistant housing, and for nations everywhere to improve oceanic and land-based early-warning systems to help minimize the risk to life

Step-by-step explanation:

what is 4% of 32? is it a percent, base, or amount

Answers

Answer:

1.28 - amount

Step-by-step explanation:

You would multiply 32 times 0.04 and get 1.28 which I assume would be an amount.

The amount of 4% of 32 is 1.28.

We have to determine what is 4% of 32.

What is the percentage?

This free percentage calculator computes a number of values involving percentages, including the percentage difference between two given values.

Suppose it is an x percent.

Therefore x multiply 32 times 0.04 and get 1.28 an amount.

To learn more about the percentage of visits:

https://brainly.com/question/24304697

#SPJ2

Valentine's Day is coming up, so Sweet Dreams chocolate shop is ordering ribbon to decorate gift boxes. Small gift boxes use 20 inches of ribbon, while large ones use 30 inches. Sweet Dreams expects to sell 225 small boxes and 180 large boxes. If the ribbon they use is sold by the yard, how many yards of ribbon should they order?

Answers

Answer:

i think 9900

Step-by-step explanation:

225x20 = 4500

180x30 = 5400

5400+4500 = 9900

A man earned £6500 for the month. He paid 2/5 in tax . How much did he have left to spend?

Answers

Answer:

$2600

Step-by-step explanation:

Im not too fond of the conversion of Pounds and USD. But if it were USD 2/5 of the amount would be $2600

Match the event with the most appropriate probability word: The roll of a normal fair dice will show a 7.

A. Certainly
B. Likely
C. Evens
D. Unlikely
E. Impossible
F. Other

Answer this, plz.

Answers

Answer:

Option 3

Evens

. . . . . .. . ..

Help please please need quick

Answers

14 times 14=196
7 times 7= 49
196-49=147
The length of X is approximately 7 root 3. Or 12.12 as a decimal

A breakfast cereal producer makes its most popular product by combining just raisins and flakes in each box of cereal. The amounts of flakes in the boxes of this cereal are normally distributed with a mean of 370\,\text{g}370g370, start text, g, end text and a standard deviation of 24\,\text{g}24g24, start text, g, end text. The amounts of raisins are also normally distributed with a mean of 170\,\text{g}170g170, start text, g, end text and a standard deviation of 7\,\text{g}7g7, start text, g, end text.
Let T=T=T, equals the total amount of product in a randomly selected box, and assume that the amounts of flakes and raisins are independent of each other.
Find the probability that the total amount of product is less than 575\,\text{g}575g575, start text, g, end text.
You may round your answer to two decimal places.
P(T<575)\approx

Answers

Using the normal distribution, it is found that there is a 0.9192 = 91.92% probability that the total amount of product is less than 575 g.

In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

It 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, which is the percentile of X.When two normal variables are added, the mean is the sum of the means while the standard deviation is the square root of the sum of the variances.

In this problem, the product is composed by flakes and raisins, and we have that:

[tex]\mu_F = 370, \sigma_F = 24, \mu_R = 170, \sigma_R = 7[/tex]

Hence, the distribution for the total amount of product has mean and standard deviation given by:

[tex]\mu = \mu_F + \mu_R = 370 + 170 = 540[/tex]

[tex]\sigma = \sqrt{\sigma_F^2 + \sigma_R^2} = \sqrt{24^2 + 7^2} = 25[/tex]

The probability that the total amount of product is less than 575 g is the p-value of Z when X = 575, hence:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{575 - 540}{25}[/tex]

[tex]Z = 1.4[/tex]

[tex]Z = 1.4[/tex] has a p-value of 0.9192.

0.9192 = 91.92% probability that the total amount of product is less than 575 g.

A similar problem is given at https://brainly.com/question/22934264

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