Suppose that 20° of boys opted for mathematics and 40% of girls opted for mathematics. What is the probability that a student opted for mathematics if half of the class is girls?​

Answer:

Step-by-step explanation:

This is a differential equation problem most easily solved with an exponential decay equation of the form

[tex]y=Ce^{kt}[/tex]. We know that the initial amount of salt in the tank is 28 pounds, so

C = 28. Now we just need to find k.

The concentration of salt changes as the pure water flows in and the salt water flows out. So the change in concentration, where y is the concentration of salt in the tank, is [tex]\frac{dy}{dt}[/tex]. Thus, the change in the concentration of salt is found in

[tex]\frac{dy}{dt}=[/tex] inflow of salt - outflow of salt

Pure water, what is flowing into the tank, has no salt in it at all; and since we don't know how much salt is leaving (our unknown, basically), the outflow at 3 gal/min is 3 times the amount of salt leaving out of the 400 gallons of salt water at time t:

[tex]3(\frac{y}{400})[/tex]

Therefore,

[tex]\frac{dy}{dt}=0-3(\frac{y}{400})[/tex] or just

[tex]\frac{dy}{dt}=-\frac{3y}{400}[/tex] and in terms of time,

[tex]-\frac{3t}{400}[/tex]

Thus, our equation is

[tex]y=28e^{-\frac{3t}{400}[/tex] and filling in 16 for the number of minutes in t:

y = 24.834 pounds of salt

Answer:

(3) $20.1 billion

Step-by-step explanation:

hope it help

Answer:

(5) $60.3 billion​

Step-by-step explanation:

Answer: I do not know what you mean, but you could do burpees, and sit ups.

Answer:

9262

Step-by-step explanation:

just plug in 22 for n and calculate

Answer:

Factoring a perfect square trinomial.

Step-by-step explanation:

The left side was able to be simplified via factoring.

[tex]\frac{13}{28}[/tex]

Given:

Blue marbles: 3

Reb marbles: 5

Total marbles: 8

Two marbles are selected at random, one after the other with replacement.

Getting the same colour of marbles from the selection means the two marbles are both red or both blue.

(a) Probability of getting 2 marbles being red in colour

i. Probability of picking a red at the first selection:

Number of red marbles ÷ Total number of marbles

=> 5 ÷ 8 = [tex]\frac{5}{8}[/tex]

ii. Probability of picking a red at the second selection:

Number of remaining red marbles ÷ Total number of remaining marbles

Since after the first pick, the marble is not replaced, the remaining red marbles is 4 while the total number of remaining marbles is 7

=> 4 ÷ 7 = [tex]\frac{4}{7}[/tex]

iii. The probability of getting both marbles being red is the product of i and ii above. i.e

[tex]\frac{5}{8}[/tex] x [tex]\frac{4}{7}[/tex] = [tex]\frac{5}{14}[/tex]

(b) Probability of getting 2 marbles being blue in colour

i. Probability of picking a blue at the first selection:

Number of blue marbles ÷ Total number of marbles

=> 3 ÷ 8 = [tex]\frac{3}{8}[/tex]

ii. Probability of picking a blue at the second selection:

Number of remaining blue marbles ÷ Total number of remaining marbles

Since after the first pick, the marble is not replaced, the remaining blue marbles is 2 while the total number of remaining marbles is 7

=> 2 ÷ 7 = [tex]\frac{2}{7}[/tex]

iii. The probability of getting both marbles being blue is the product of i and ii above. i.e

[tex]\frac{3}{8}[/tex] x [tex]\frac{2}{7}[/tex] = [tex]\frac{3}{28}[/tex]

(c) Probability of getting 2 marbles of the same colour.

The probability of getting 2 marbles of same colour is the sum of the probability of getting both marbles of red colour and the probability of getting both marbles as blue colour. i.e The sum of a(iii) and b(iii)

[tex]\frac{5}{14}[/tex] + [tex]\frac{3}{28}[/tex] = [tex]\frac{13}{28}[/tex]

The probability of getting 2 of the same colour is [tex]\frac{13}{28}[/tex]

Answer:

16 years

Step-by-step explanation:

Given that :

Earth's distance from sun = 93 million miles

Number of years to complete an orbit = 1 year

Average orbiting distance of new asteroid = 1488 million miles

Number of years to complete an orbit = x

93,000,000 Miles = 1

1488000000 miles = x

Cross multiply :

93000000x = 1488000000

x = 1488000000 / 93000000

x = 16 years

Period taken to orbit the sun = 16 years

Answer: 64 Earth years...

Answer:

5040

Step-by-step explanation:

I assume you really mean 7!

you understand what "!" means ?

n! = n×(n-1)×(n-2)×(n-3)×...×3×2×1

so,

7! = 7×6×5×4×3×2×1

now all you need is a calculator.

7! = 5040

Answer:

9 ft^2 and 12.25 ft^2

Step-by-step explanation:

We need to figure out the area for a square with a perimeter of 12 feet and 14 feet.

A square has four sides that are all equal in length, therefore:

12/4 = 3

14/4 = 3.5

3 and 3.5 are the individual side lengths of the garden, so to find the area, we just multiply those numbers by themselves (since it is a square garden).

3*3 = 9

3.5*3.5 = 12.25

Therefore, the answer is 9 ft^2 and 12.25 ft^2

Answer:

The numerical limits for a B grade are 81 and 89, that is, a score between 81 and 89 gets a B grade.

Step-by-step explanation:

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 z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Scores on the test are normally distributed with a mean of 79.7 and a standard deviation of 8.4.

This means that [tex]\mu = 79.7, \sigma = 8.4[/tex]

B: Scores below the top 13% and above the bottom 56%

So between the 56th percentile and the 100 - 13 = 87th percentile.

56th percentile:

X when Z has a p-value of 0.56, so X when Z = 0.15. Then

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

[tex]0.15 = \frac{X - 79.7}{8.4}[/tex]

[tex]X - 79.7 = 0.15*8.4[/tex]

[tex]X = 81[/tex]

87th percentile:

X when Z has a p-value of 0.87, so X when Z = 1.13.

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

[tex]1.13 = \frac{X - 79.7}{8.4}[/tex]

[tex]X - 79.7 = 1.13*8.4[/tex]

[tex]X = 89[/tex]

The numerical limits for a B grade are 81 and 89, that is, a score between 81 and 89 gets a B grade.

Answer:

16 cm

Step-by-step explanation:

4 + 4 + 3 + 5 = 16

The = sign means that B (which is 4 cm) is equal to D (which had no number)

And because it says that B = D (with the squiggly line (or a tilde)) And the L's (which means that the letters represent an angle) All you have to do is add the numbers together, and you get 16.

Sorry if I explained it badly, you at least got the answer.

(And also, if I'm wrong, please tell me.)

Answer:

P = 32 cm

Step-by-step explanation:

Im just putting the right answer up so you don't accidentally put in the wrong one.

Answer:

See explanation

Step-by-step explanation:

The question is incomplete, as the vertices of the triangle are not given.

A general explanation is as follows;

To calculate distance between two points, we use:

[tex]d = \sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}[/tex]

Take for instance;

[tex]A = (1,4)[/tex]

[tex]B = (3,-2)[/tex]

Distance AB is:

[tex]AB = \sqrt{(1 - 3)^2 + (4 - -2)^2}[/tex]

[tex]AB = \sqrt{(- 2)^2 + (4 +2)^2}[/tex]

[tex]AB = \sqrt{(- 2)^2 + (6)^2}[/tex]

Evaluate the exponents

[tex]AB = \sqrt{4 + 36}[/tex]

[tex]AB = \sqrt{40}[/tex]

[tex]AB = 6.32[/tex]

Answer:

for edmentum

Step-by-step explanation:

Answer:

300 + 15x = 500

15x = 200

x = 200/15

x=13.333

14 pair of shoes

Step-by-step explanation:

Answer:

Amount should be reported in investing activities = $173,000

Step-by-step explanation:

Given:

Amount of land costing = $140,000

Sold amount of land = $173,000

Find:

Amount should be reported in investing activities

Computation:

Amount should be reported in investing activities = $173,000

The cash flow statement shows how much money is coming in and going out. The whole amount of cash received, which is 173,000 dollars, will be recorded as proceeds from the sale of land in the investment activity. As a result, the right answer is 173,000.

Answer:

The warranty period should be of 30 months.

Step-by-step explanation:

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 z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Optimal-Eats blender has a mean time before failure of 37 months with a standard deviation of 5 months.

This means that [tex]\mu = 37, \sigma = 5[/tex]

What should be the warranty period, in months, so that the manufacturer will not have more than 7% of the blenders returned?

The warranty period should be the 7th percentile, which is X when Z has a p-value if 0.07, so X when Z = -1.475.

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

[tex]-1.475 = \frac{X - 37}{5}[/tex]

[tex]X - 37 = -1.475*5[/tex]

[tex]X = 29.6[/tex]

Rounding to the nearest whole number, 30.

The warranty period should be of 30 months.

Answer:

B - 82%

Step-by-step explanation:

.34+.48

The percentage of people who can swim is 82%.

Option B is the correct answer.

The percentage means the required value out of 100.

It is calculated by dividing the required value by the total value and multiplying it by 100.

The percentage change is also calculated using the same method.

In percentage change, we find the difference between the values given.

Example:

Required percentage value = a

total value = b

Percentage = a/b x 100

We have,

The relative frequency table shows the proportion of people in each group who can and cannot swim.

To find the percentage of people who can swim, we need to add up the proportion of adults who can swim (0.34) and the proportion of children who can swim (0.48).

Percentage of people who can swim

= (0.34 + 0.48) x 100%

= 82%

Therefore,

The percentage of people who can swim is 82%.

Learn more about percentages here:

https://brainly.com/question/11403063

#SPJ5

To find the simple interest we'll plug it into one of the two available formulas. I will use both formulas so you can determine which is easiest for you, for future problems.

                                     r = I/Pt         or     I = Prt

                                     (the / represents division)

Let's define and plug.

r = the rate (we'll be solving for r)

I = the total interest earned within the time frame ($2)

P= the principal amount ($100)

t = the total time the principal accrued interest. (6 months/ .5years)

**Because this is in a monthly basis, lets change it into a year to make it easier**

we'll just divide 6 months by 12 months.

6 ÷ 12 = 0.5 years

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

Let's use the first formula first. r = I / Pt

r = 2 / 100 (0.5)

100 x 0.5 = 50

We're now left with:            r = 2 / 50

Divide what we have left.

2 ÷ 50 = 0.04

This is our simple interest but we have to convert it into a percentage. To convert the decimal to the percentage, we'll move the decimal two places to the right to  make 4.0.

Therefore, our simple interest would be 4%

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

let's set up the second formula:  I = Prt

2 = 100 (r) (0.5)

2 = 50 (r)

2 ÷ 50 = 0.04

0.04 in percentage = 4%

Answer:

Function has a minimum value

So, f(x)=0 and f(4)=-3

f(4)=-3 and f(x)=-x+4

f(4)=0

OAmalOHopeO

Answer:

[tex]A = \left[\begin{array}{cccc}1&-1&-3&-5\\4&2&0&-2\\7&5&3&1\end{array}\right][/tex]

Step-by-step explanation:

A = (aij)

i representa a linha e j a coluna.

Tipo 3x4

Isto implica que a matriz tem 3 linhas e 4 colunas.

aij = 3i – 2j.

Primeira linha:

[tex]a_{1,1} = 3(1) - 2(1) = 1[/tex]

[tex]a_{1,2} = 3(1) - 2(2) = -1[/tex]

[tex]a_{1,3} = 3(1) - 2(3) = -3[/tex]

[tex]a_{1,4} = 3(1) - 2(4) = -5[/tex]

Segunda linha:

[tex]a_{2,1} = 3(2) - 2(1) = 4[/tex]

[tex]a_{2,2} = 3(2) - 2(2) = 2[/tex]

[tex]a_{2,3} = 3(2) - 2(3) = 0[/tex]

[tex]a_{2,4} = 3(2) - 2(4) = -2[/tex]

Terceira linha:

[tex]a_{3,1} = 3(3) - 2(1) = 7[/tex]

[tex]a_{3,2} = 3(3) - 2(2) = 5[/tex]

[tex]a_{3,3} = 3(3) - 2(3) = 3[/tex]

[tex]a_{3,4} = 3(3) - 2(4) = 1[/tex]

Matriz:

A matriz é dada por:

[tex]A = \left[\begin{array}{cccc}1&-1&-3&-5\\4&2&0&-2\\7&5&3&1\end{array}\right][/tex]

Answer:

4+4+8+8+422+33+65520222222+222= 65,520,222,923

Answer:

Equation: f(x) = 2(x + 5)^2 + 2

Vertex: (-5, 2)

Step-by-step explanation:

The form the question wants us to write the quadratic function in is called "vertex form":

f(x) = a (x - h)^2 + k

a = the a in a standard quadratic equation (y = ax^2 + bx + c) or the coefficient of the x^2

h = x coordinate of the vertex

k = y coordinate of the vertex

To find the vertex, we are going to use the quadratic equation given:

2x^2 + 20x + 52

Comparing it to the standard quadratic equation (y = ax^2 + bx + c),

a = 2

b = 20

c = 52

Now we can start finding our vertex.

To find h, we are going to use this formula:

-b / 2a

We already know b = 20 & a = 2, so we can just substitute that into our formula:

- (20) / 2*2

Which equals:

-20/4 = -5

So h (or the x coordinate of the vertex) is equal to -5

Next we will find k, or the y coordinate of the vertex.

To do that, we are going to plug in -5 into 2x^2 + 20x + 52:

2(-5)^2 + 20(-5) + 52

2(25) -100 + 52

50 - 100 + 52

-50 + 52

2

k (or the y coordinate of the vertex) is equal to 2

The vertex is (-5, 2)

However, we still need to find our equation in vertex form.

We know a = 2, h = -5, & k = 2. Now we substitute these into our vertex form equation:

a(x - h)^2 + k

(2)(x - (-5))^2 + (2)

2(x + 5)^2 + 2

(Remember that the -5 cancels with the - in front of it, making it a positive 5)

The equation is f(x) = 2(x + 5)^2 + 2

Hope it helps (●'◡'●)

Answer:

so the answer is 0.16339

Answer:

Step-by-step explanation:

As due to congruency,

x + 3 = 3y

[By putting the values of x = 3 and y = 2]

=> 3 + 3 = 3 × 2

=> 6 = 6

and,

x = y + 1

[By putting the values of x = 3 and y = 2]

=> 3 = 2 + 1

=> 3 = 3

Hence, proved

Answer:

2n+2

_____

9 2n

Answer:

I am assuming that you meant to write π/5.

Step-by-step explanation:

Radius r = 5 meters

Circumference = 2πr = 10π

Central angle θ = π/5 radian

Arc length = 10π × θ/(2π radians)

= 5θ

= π meters

Answer:

a) 0.46 = 46% probability that a person who walks by the store will enter the store.

b) 0.36 = 36% probability that a person who walks into the store will buy something.

c) 0.17 = 17% probability that a person who walks by the store will come in and buy something.

d) 0.64 = 64% probability that a person who comes into the store will buy nothing.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

(a) Estimate the probability that a person who walks by the store will enter the store.

58 out of 125. So

[tex]p = \frac{58}{125} = 0.46[/tex]

0.46 = 46% probability that a person who walks by the store will enter the store.

(b) Estimate the probability that a person who walks into the store will buy something.

58 walked, 21 bought. So

[tex]p = \frac{21}{58} = 0.36[/tex]

0.36 = 36% probability that a person who walks into the store will buy something.

(c) Estimate the probability that a person who walks by the store will come in and buy something.

21 came in and bought out of 125 that walked by. So

[tex]p = \frac{21}{125} = 0.17[/tex]

0.17 = 17% probability that a person who walks by the store will come in and buy something.

(d) Estimate the probability that a person who comes into the store will buy nothing.

0.36 probability that a person buys something, so 1 - 0.36 = 0.64 = 64% probability that a person who comes into the store will buy nothing.

Answer:

18 feet

Step-by-step explanation:

The question is  illustrated using the attached image.

From the image, we have:

[tex]\theta = 31.43^o[/tex] --- angle of depression

[tex]h = 11ft[/tex] --- Emir's height

Required

The distance from the base of the tree (x)

From the attached triangle, we have:

[tex]\tan(90 - \theta) = \frac{Opposite}{Adjacent}[/tex]

This gives:

[tex]\tan(90 - 31.43) = \frac{x}{11}[/tex]

[tex]\tan(58.57) = \frac{x}{11}[/tex]

Make x the subject

[tex]x = 11 * \tan(58.57)[/tex]

[tex]x = 18.00[/tex]

Answer:

18

Step-by-step explanation:

took the test