Please help with either of these questions. Put the answer in the comments please

Answer:

Amanda buy first kind of pen = 3

Amanda buy second kind of pen = 2

Amanda buy third kind of pen = 15

Step-by-step explanation:

Given - Amanda went to the store to purchase ink pens. She found three    

            kinds of pens. The first cost $4 each; the price of the second kind

            was 4 for $1; and the cost for the third kind was 2 for $1. She bought

            20 pens and she bought at least one of each kind. (It is possible to

            buy only 1 of the pens that are "4 for $1" or "2 for $1".) The cost was

            $20.

To find - When she got back to her office, Amanda decided to turn this into

              a math problem for me. She asked: how many of each kind did I

              buy?

Proof -

Let Amanda buy first kind of pen = x

                      second kind of pen = y

                           third kind of pen = z

As given,

She bought total pen = 20

⇒x + y + z = 20          ...............(1)

Now,

As given,

cost for first kind pen = $4 for 1 pen

As she bought x pens of first kind , so

Cost of x pens of first kind = $4x

Now,

The price of the second kind was 4 for $1

⇒Cost of second kind = $[tex]\frac{1}{4}[/tex] for 1 pen

As she bought y pens of send kind , so

Cost of y pens of second kind = $[tex]\frac{1}{4}y[/tex]

Now,

The price of the third kind was 2 for $1

⇒Cost of third kind = $[tex]\frac{1}{2}[/tex] for 1 pen

As she bought z pens of send kind , so

Cost of z pens of third kind = $[tex]\frac{1}{2}z[/tex]

Now,

As given, The cost was $20

⇒4x + [tex]\frac{1}{4}y[/tex] + [tex]\frac{1}{2}z[/tex] = 20

⇒16x + y + 2z = 80             .....................(2)

∴ we get 2 equations

x + y + z = 20                   .....................(1)

16x + y + 2z = 80             .....................(2)

Now,

Subtract equation (1) from equation (2) , we get

16x + y + 2z  - ( x+ y + z )= 80 - 20

⇒16x + y + 2z - x - y - z = 60

⇒15x + z = 60

⇒z = 60 - 15x

Now,

Put the value of z in equation (1) , we get

x + y + 60 - 15 x = 20

⇒ y - 14x = 20 - 60

⇒y - 14x = -40

⇒14x - y = 40

⇒y = 14x - 40

Now,

we get

z = 60 - 15x

y = 14x - 40

As given

she bought at least one of each kind

it means x > 1, y > 1, z > 1

Now,

If x = 1, then y = 14 - 40 = -26

Not possible

If x = 2 , then y = 14(2) - 40 = -12

Not possible

If x = 3, then y = 14(3) - 40 = 2 and z = 60 - 15(3) = 15

Possible.

If x = 4,  then y = 14(4) - 40 = 16 and z = 60 - 15(4) = 0

Not Possible.

If x = 5, then y = 14(5) - 40 = 30 and z = 60 - 15(5) = -15

Not Possible.

∴ we get

x = 3, y = 2, z = 15

Amanda buy first kind of pen = x = 3

Amanda buy second kind of pen = y = 2

Amanda buy third kind of pen = z = 15

Answer:

Not completely sure for the rest, but I believe the range is incorrect: the range represents y-values, not x-values.

So it should be 0 ≤ y ≤ π

Answer:

Given that 1minute =3/7of the vessel

let the time taken in minutes to fill the whole of the vessel be' x' minute.

1min =3/7

xmin =whole vessel =1=7/7

=3x/7=1=x=7/3=2.3min=2min.3sec

If [tex]h(t)=3[/tex] then [tex]h(4)=3[/tex]

(8*P) + (0.25*m)=C

P = People

Answer:

Step-by-step explanation:

A community center offers yoga classes for $8 per month plus an additional $0.25 per center floor mat used.Write an equation to express this relationship, using m to represent the number of mats used per month and C to represent the total cost in dollars.

Answer:

8

Step-by-step explanation:

Answer:

1 3/4 x 8 = 14. In 10 days, he will be paid the amount of one day x 10. 14 x 10 = 140. Tom will be paid $140 in 10 days

Step-by-step explanation:

Answer:

hold on im trying to solve it

Step-by-step explanation:

Answer:

65

Step-by-step explanation:

2(65) = 130

180-130 = 65

hope this helps plz mark brainliest!

Answer:

1..............................

Answer:

it's A!!!

Step-by-step explanation:

hoped I helped

Answer:

The anwser is A.

Step-by-step explanation:

4x+y=6 and x-2y=6 so the answer is 2, and -2

Answer:

Answer: Janet is 16, and David is 11.

Step-by-step explanation:

Let the ages be j and d.

j = d + 5

j + d = 27

Substitute d + 5 for j in the second equation.

d + 5 + d = 27

2d + 5 = 27

2d = 22

d = 11

Substitute 11 for d in the first equation.

j = d + 5

j = 11 + 5

j = 16

Answer: Janet is 16, and David is 11.

Answer:

9% of 124 is 11.16

Answer: 128 people

Step-by-step explanation:

every 2 people get a gallon so 2*64=128

Answer:

what do you need help with?

Step-by-step explanation:

**you will get a real answer i promise**:)

Answer:

I don't understand the problem

9514 1404 393

Answer:

  x = 7

Step-by-step explanation:

The sum of angle measures in a quadrilateral is 360°.

  (8x-5)° +107° +83° +119° = 360°

  8x = 56 . . . . . . . divide by °, subtract 304

  x = 7 . . . . . . . . . . divide by 8

Find the area of the base [tex]A=64\pi[/tex].

Multiply area of the base by height to get volume

[tex]V=20\cdot64\pi=4021.24[/tex]

Hope this helps.

Answer:

1138050

Step-by-step explanation:

Multiply 843,000 by 0.35 and then add the numbers together.

Please mark brainliest

Answer:

strongly skewed right

Step-by-step explanation:

since the sample size is under 30, it will remain skewed right.

The shape of the distribution of the sample mean for all possible random samples of size 10 from this population is strongly skewed right.

It should be noted that sampling simply means the selection process from a particular population.

In this case, the shape of the distribution of the sample mean for all possible random samples of size 10 from this population is strongly skewed right. This is because the sample size is under 30.

Learn more about sampling on:

https://brainly.com/question/24466382

Answer:

9

Step-by-step explanation:

2x+3=3x-6

3+6=3x-2x

9=x

Answer:

x=  9

Step-by-step explanation:

hello :

2x +3 = 3x -6

2x-3x=-6-3

-x= -9

so : x=  9

Answer:

64 miles per hour.

Step-by-step explanation:

we are asked to look for the velocity of this car. to find it, we use the equation [tex]velocity = \frac{distance}{time}[/tex]. we substitute the given to the equation:

[tex]velocity = \frac{224 m}{3.5 hr}[/tex]

velocity = 64 miles per hour

Answer:

Step-by-step explanation:

4×1½×2 = 4×3 = 12

Answer:

A

Step-by-step explanation:

hryhrhdvshzhsbdyxhdbdhxhbd

Answer:

A

Step-by-step explanation:

i dunno but its right! stay safe stay healthy <3

9514 1404 393

Answer:

  0, 1, 2, 3

Step-by-step explanation:

The set of absolute values of integers is the set of non-negative integers. The four smallest values of the set are ...

  0, 1, 2, 3

Answer:

x=98

Step-by-step explanation:

all interior angles in a hexagon equals 720, just subtract 720 by every known angle and you are left with the unknown angle

Answer:

I believe the answer is 5.657 square inches.

Step-by-step explanation:

Answer:

0.3409 = 34.09% probability that under 70% color their hair in a group of 85 older women.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the Central Limit Theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

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.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex].

72% report that they color their hair to hide their gray.

This means that [tex]\mu = p = 0.72[/tex]

What is the probability that under 70% color their hair in a group of 85 older women?

For a sample of 85, we have that [tex]s = \sqrt{\frac{0.72*0.28}{85}} = 0.0487[/tex]

This probability is the pvalue of Z when X = 0.7. So

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

By the Central Limit Theorem

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

[tex]Z = \frac{0.7 - 0.72}{0.0487}[/tex]

[tex]Z = -0.41[/tex]

[tex]Z = -0.41[/tex] has a pvalue of 0.3409

0.3409 = 34.09% probability that under 70% color their hair in a group of 85 older women.