in a class of 40 students, 30 students read chemistry, 40 students read physics, if all students read at least one of the subject, find the probability a students is selected at random will read only chemistry ​

Answer:

A

Step-by-step explanation:

hope this help

Answer:

absolutely convergent

Step-by-step explanation:

given data

sin(n)/3^n

solution

we have given term [tex]\frac{sin(n)}{3^n}[/tex]

when n = 1

and we know that

value of sin(n) ≤ 1

so that we can say that

[tex]\frac{sin(n)}{3^n}[/tex]  ≤  [tex]\frac{1}{3^n}[/tex] or [tex](\frac{1}{3})^n[/tex]

here [tex]\frac{1}{3^n}[/tex]  is converges this is because common ratio in geometric series

here r is [tex]\frac{1}{3}[/tex]  and here it satisfy that -1 < r < 1

so it is converges

and

[tex]\frac{sin(n)}{3^n}[/tex]  is also similar

so it is  converges

and here no [tex](-1)^n[/tex]  term is

so we can say series is absolutely convergent

Answer:

x = 6

Step-by-step explanation:

∠ DBC + ∠ ABC = ∠ ABD , substitute values

5x - 4 + 8x - 3 = 79

13x + 1 = 79 ( subtract 1 from both sides )

13x = 78 ( divide both sides by 13 )

x = 6

Answer:

=  -2w + 22

Step-by-step explanation:

  -3(2w - 6) + 4(w+1)

= (-3*2w -3*-6) + (4*w + 4*1)

=  -6w + 18 + 4w + 4

= -6w + 4w + 18 + 4

= -2w + 22

Answer:

137, 280 feet

Step-by-step explanation:

There are 5,280 feet in a mile.

26 * 5,280 = 137,280

There are 137, 280 feet in 26 miles.

There are 137,280 feet in 26 miles.

The unitary method is a method for solving a problem by the first value of a single unit and then finding the value by multiplying the single value.

We know that there are 5,280 feet in a mile.

So, the solution would be;

26 x 5,280 = 137,280

Thus, There are 137,280 feet in 26 miles.

Learn more about the unitary method;

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Answer:

7:41

Step-by-step explanation:

8:08 - 7 Minutes = 8:01

8:01 - 20 Minutes = 7:41

Answer:

(7 x 2.85) + 5v = 28.70. 19.95 + 5v = 28.70. 5v = 28.70 - 19.95. 5v = 8.75. v = 8.75/5. v = 1.75. A pint of veggies costs $1.75.

Answer:

a₃ = 9

Step-by-step explanation:

The numbers in the set are referred to as { a₁, a₂, a₃, ... }

Answer:

Answer:

51.

Step-by-step explanation:

f(x) = x^2 + 2x + 3 and g(x) = x + 4.

f(g(x)) = (x + 4)^2 + 2(x + 4) + 3

= x^2 + 4x + 4x + 16 + 2x + 8 + 3

= x^2 + 8x + 16 + 2x + 11

= x^2 + 10x + 27.

x = 2.

f(g(2)) = 2^2 + 10 * 2 + 27

= 4 + 20 + 27

= 31 + 20

= 51.

Hope this helps!

Answer:

There is not sufficient sample evidence to support the claim that the population mean is not equal to 88.9.

Step-by-step explanation:

We are given the following hypothesis below;

Let [tex]\mu[/tex] = population mean.

So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] = 88.9      {means that the population mean is equal to 88.9}

Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu\neq[/tex] 88.9     {means that the population mean is different from 88.9}

The test statistics that will be used here is One-sample t-test statistics because we don't know about population standard deviation;

                             T.S.  =  [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex]  ~  [tex]t_n_-_1[/tex]

where, [tex]\bar X[/tex] = sample mean = 81.3

             s = sample standard deviation = 13.4

            n = sample size = 7

So, the test statistics =  [tex]\frac{81.3-88.9}{\frac{13.4}{\sqrt{7} } }[/tex]   ~ [tex]t_6[/tex]

                                     =  -1.501

The value of t-test statistics is -1.501.

Also, the P-value of the test statistics is given by;

                    P-value = P([tex]t_6[/tex] < -1.501) = 0.094

Since the P-value of our test statistics is more than the level of significance as 0.094 > 0.01, so we have insufficient evidence to reject our null hypothesis as the test statistics will not fall in the rejection region.

Therefore, we conclude that the population mean is equal to 88.9.

Answer/Step-by-step explanation:

Given, [tex] b(x) = (\frac{6}{7})^{x} [/tex]

The table for the function are:

When x = -2

[tex] b(-2) = (\frac{6}{7})^{-2} [/tex]

[tex] b(-2) = \frac{1}{(\frac{6}{7})^{2}} [/tex]

[tex] b(-2) = \frac{1}{(\frac{36}{49})} [/tex]

[tex] b(-2) = 1*\frac{49}{36} [/tex]

[tex] b(-2) = \frac{49}{36} [/tex]

When x = -1

[tex] b(-1) = (\frac{6}{7})^{-1} [/tex]

[tex] b(-1) = \frac{1}{(\frac{6}{7})} [/tex]

[tex] b(-1) = 1*\frac{7}{6} [/tex]

[tex] b(-2) = \frac{7}{6} [/tex]

When x = 0

[tex] b(0) = (\frac{6}{7})^{0} [/tex]

[tex] b(0) = \frac{6^0}{7^0} [/tex]

[tex] b(0) = \frac{1}{1} [/tex]

[tex] b(0) = 1 [/tex]

When x = 1

[tex] b(1) = (\frac{6}{7})^{1} [/tex]

[tex] b(1) = \frac{6}{7} [/tex]

When x = 2

[tex] b(2) = (\frac{6}{7})^{2} [/tex]

[tex] b(2) = \frac{6^2}{7^2} [/tex]

[tex] b(2) = \frac{36}{49} [/tex]

Step-by-step explanation:

for finding the weight of 12 boxes multiply 12 with the weight of first box and then you will get your answer. Tell me the answer which you found and if it will be correct I will say ok if not I will give you the correct answer

Answer:

The answer is 18 feet

Step-by-step explanation:

To find the diameter of a circle given it's radius we use the formula

diameter = radius × 2

From the question

radius = 8

So the diameter is

Hope this helps you

Answer:

18

Step-by-step explanation:

Hey there!

Well radius is half the diameter so,

D = r*2

Plug in 9

D = 9*2

D = 18

Hope this helps :)

Answer:

9%

Step-by-step explanation:

Use the rule of 72.  If you want the money to double in 8 years, it will need to be at 9 percent interest rate to reach this goal.

Answer:  Statement 1: postulate; Statement 2: definition

Step-by-step explanation:

Here, Statement 1:If parallel lines have a transversal, then corresponding angles are congruent.

which is a fact, and hence it is postulate.

Statement 2: A line has an infinite number of points extending in opposite directions.

which is an explanatory statement of a 'line', hence it is 'definition.

So the correct option is Statement 1: postulate; Statement 2: definition

Answer:statement 1 and statement 2 postulate

Step-by-step explanation:

[tex](f\circ g)(2)=\dfrac{1}{4\cdot2+9}=\dfrac{1}{17}\\\\(f+g)(2)=\dfrac{1}{2}+4\cdot2+9=\dfrac{1}{2}+17=\dfrac{1}{2}+\dfrac{34}{2}=\dfrac{35}{2}[/tex]

Answer:

x = 3

Step-by-step explanation:

-40 = -8 (x + 2)

-8 (x + 2) = -40   --- divide both sides by - 8

-8 (x + 2)           -40

--------------   =   ----------

      -8                  -8

x + 2 = 5    --- subtract 2 from both sides

x + 2 - 2 = 5 - 2   then simplify

x = 3

Answer:

x=3

Step-by-step explanation:

First, write out the equation as you have been given it:

[tex]-40=-8(x+2)[/tex]

Then distribute the -8 to the terms inside the parenthesis:

[tex]-40=-8x-16[/tex]

Next, add 16 to both sides:

[tex]-40+16=-8x-16+16\\-24=-8x[/tex]

Finally, divide both sides by -8:

[tex]\frac{-24}{-8}=\frac{-8x}{-8}\\3=x[/tex]

Therefore, x=3.

Step-by-step explanation:

C = Amount (A) - Principal (P)

Where

C is the compound interest

To find the amount we use the formula

[tex]A = P ({1 + \frac{r}{100} })^{n} [/tex]

where

P is the principal

r is the rate

n is the period / time

From the question

P = Rs 12, 000

r = 5%

n = 3 years

Substitute the values into the above formula

That's

[tex]A = 12000 ({1 + \frac{5}{100} })^{3} \\ A = 12000(1 + 0.05)^{3} \\ A = 12000 ({1.05})^{3} [/tex]

We have the answer as

Compound interest = 13891.50 - 12000

Hope this helps you

Answer:

44°

Step-by-step explanation:

Given:

m<DOC = 44°

m<COB = 80°

Required:

Angle measure of arc DC

SOLUTION:

A central angle is said to be equal to the angle measure of the arc it intercepts or corresponds with. Therefore, angle measure of arc DC = m<DOC.

measure of arc DC = 44°

Answer:

3.1 rounded off to the nearest whole number is 3.

Step-by-step explanation:

Answer:

ray is the answer for this

opposite rays form a line because they provide the two opposite directions in which the line extends infinitely.

Opposite rays are two rays that have the same endpoint but extend in opposite directions. When these opposite rays are extended infinitely in both directions, they form a straight line. A line is a set of points that extends infinitely in both directions, and opposite rays provide the two distinct directions in which the line can be extended.

The concept of opposite rays is derived from the concept of a line. A line can be defined as a straight path that extends infinitely in both directions. Opposite rays are a pair of rays that share a common endpoint and extend infinitely in opposite directions along this line.

For example, consider a line segment AB. If we extend one side of the line segment from point A and the other side from point B, we obtain two opposite rays: one from point A to infinity and the other from point B to infinity. Together, these opposite rays form the line on which the line segment AB lies.

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Answer:

  subtracting 56 instead of adding (or adding wrong)

Step-by-step explanation:

She wrote ...

  x - 56 = 230

  x - 56 - 56 = 230 -56 . . . . correct application of the addition property*

  x = 230 -56 . . . . . . . . . . . . incorrect simplification

Correctly done, the third line would be ...

  x -112 = 174

This would have made Sherina realize that the error was in subtracting 56 instead of adding it. The correct solution would be ...

  x - 56 + 56 = 230 + 56 . . . using the addition property of equality

  x = 286 . . . . . . . . . . . . . . . . correct simplification on both sides

__

There were two errors:

  1) incorrect strategy --- subtracting 56 instead of adding

  2) incorrect simplification --- simplifying -56 -56 to zero instead of -112

We don't know whether you want to count the error in thinking as the first error, or the error in execution where the mechanics of addition were incorrectly done.

_____

* The addition property of equality requires the same number be added to both sides of the equation. Sherina did that correctly. However, the number chosen to be added was the opposite of the number that would usefully work toward a solution.

Answer:

D: Sherina should have added 56 to both sides of the equation.

Step-by-step explanation:

I got a 100% on my test.

I hope this helps.

should be 2 3 andd 5

think of the - (- as a plus sign (this is what i was always taught) to add them so it would in turn be (-5) + 12 which equals 7 and choice 3 and 5 also equal this

Answer:

see below

Step-by-step explanation:

First we need to find the slope

m = ( y2-y1)/ ( x2-x1)

   = (60-64)/( 10-0)

   = -6/10

   = -2/5

The y intercept is (0,64)

The slope intercept form of the equation is

y = mx+b  where m is the slope and b is the y intercept

y = -2/5 x + 64  where y is in the thousands of feet

m = -2/5 * 1000 = -400 ft / minute

The height decreases since the sign is negative

The height decreases 400 ft per minute

The y intercept is (0,64)

64 is in the thousands of ft

64*1000 = 64,000 ft

When it starts, it is at 64,000 ft

The descent starts at a cruising altitude of 64,000 ft

A = 1 and 8

B = 2 and 4

C = 2 and 7

I’m pretty sure this is right? I’m still learning too :p

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

Explanations:

For the sake of simplicity, imagine that lines m and n are parallel. They don't necessarily need to be in order to answer this problem, but it might help with the terminology better.

When we use the term "interior" we basically mean the region between or inside the parallel lines. So "exterior" is everything but that, which is composed of two separate regions that don't overlap. Exterior angles shown in this diagram are

angle 1, angle 5, angle 4, angle 8

The "alternate" refers to the idea that we're on alternate sides of the transversal cutting line. One pair of alternate exterior angles is angle 1 and angle 8. We have angle 1 below the transversal while angle 8 is on the opposite side and above the transversal. For similar reasoning, angles 5 and 4 are alternate exterior angles as well.

---------------------------------

Notice how each line crosses to form an X shape, producing 4 angles that share the same common vertex point. For instance, angles 1, 5, 6 and 2 are all around the same point.

Angle 1 and angle 3 are corresponding angles because they

So in short, they are both in the same corner of each four corner angle configuration. They are both in the bottom left corner. This is the full list of all corresponding angle pairs

---------------------------------

As stated in the first section above, the interior region is between the parallel lines. Alternate interior angles alternate being above and below the transversal line.

So this applies to angle 2 and angle 7. It also works for angle 3 and angle 6.

Answer:

[tex]X=\begin{bmatrix}5\\ 14\\ -10\end{bmatrix}[/tex]

Step-by-step explanation:

Our approach here is to isolate X, and simplify this solution. We want to begin by subtracting matrix 2, as shown below, from either side - the first step in isolating X. Afterwards we can multiply either side by the inverse of matrix 1, the co - efficient of X, such that X is now isolated. We can then simplify this value.

Given,

[tex]\begin{bmatrix}1&2&3\\ -3&5&5\\ \:\:\:3&-2&-1\end{bmatrix}[/tex] : Matrix 1

[tex]\begin{bmatrix}3\\ -1\\ 8\end{bmatrix}[/tex] : Matrix 2

[tex]\begin{bmatrix}1&2&3\\ -3&5&5\\ 3&-2&-1\end{bmatrix}X+\begin{bmatrix}3\\ -1\\ 8\end{bmatrix}=\begin{bmatrix}6\\ 4\\ 5\end{bmatrix}[/tex] ( Subtract Matrix 2 from either side )

[tex]\begin{bmatrix}1&2&3\\ -3&5&5\\ 3&-2&-1\end{bmatrix}X=\begin{bmatrix}6\\ 4\\ 5\end{bmatrix}-\begin{bmatrix}3\\ -1\\ 8\end{bmatrix}[/tex] ( Simplify )

[tex]\begin{bmatrix}6\\ 4\\ 5\end{bmatrix}-\begin{bmatrix}3\\ -1\\ 8\end{bmatrix} = \begin{bmatrix}6-3\\ 4-\left(-1\right)\\ 5-8\end{bmatrix}=\begin{bmatrix}3\\ 5\\ -3\end{bmatrix}[/tex] ( Substitute )

[tex]\begin{bmatrix}1&2&3\\ -3&5&5\\ 3&-2&-1\end{bmatrix}X=\begin{bmatrix}3\\ 5\\ -3\end{bmatrix}[/tex] ( Multiply either side by inverse of Matrix 1 )

[tex]X=\begin{bmatrix}1&2&3\\ -3&5&5\\ 3&-2&-1\end{bmatrix}^{-1}\begin{bmatrix}3\\ 5\\ -3\end{bmatrix}=\begin{bmatrix}5\\ 14\\ -10\end{bmatrix}[/tex] - let's say that this is Matrix 3. Our solution would hence be Matrix 3.

Answer:

t= 0.4933

t ≥ t ( 0.025 ,8 ) = 2.306

Since the calculated value of t= 0.4933 is less than t ( 0.025 ,8 ) = 2.306 therefore we accept the null hypothesis at 5 % significance level . On the basis of this we conclude that the book had no effect on their scores.

Step-by-step explanation:

We state our null and alternative hypotheses as

H0: ud= 0 Ha: ud≠0

The significance level is set at ∝= 0.05

The test statistic under H0 is

t= d`/ sd/√n

which has t distribution with n-1 degrees of freedom

The critical region is t ≥ t ( 0.025 ,8 ) = 2.306

Computations

Student       Scores before      Scores after    Difference           d²

                        reading book                    ( after minus before)

1                          720                   740             20                       400

2                        860                   860              0                           0

3                        850                   840             -10                       100

4                        880                   920             40                       1600

5                        860                   890             30                        900

6                        710                    720              10                         100

7                       850                    840              -10                       100

8                      1200                  1240             40                        1600

9                      950                    970              20                           40

∑                    6930                  8020           140                         4840

d`= ∑d/n= 140/9= 15.566

sd²= 1/8( 4840- 140²/9) = 1/8 (4840 - 2177.778) = 2662.22/8= 332.775

sd= 18.2422

t= 3/ 18.2422/ √9

t= 0.4933

Since the calculated value of t= 0.4933 is less than t ( 0.025 ,8 ) = 2.306 therefore we accept the null hypothesis at 5 % significance level . On the basis of this we conclude that the book had no effect on their scores.

Answer:

The  number of rainfalls is [tex]n =96[/tex]

The answer to the second question is  no it will not be valid this because from the question we are told that the experiment require one pH reading per rainfall so getting multiply specimens(used for the  pH reading) from  one rainfall will make the experiment invalid.

Step-by-step explanation:

from the question we are told that

    The  standard deviation is  [tex]\sigma = 0.5[/tex]

     The  margin of error is  [tex]E = 0.1[/tex]

Given that the confidence level is  95%  then we can evaluate the level of significance as

                  [tex]\alpha = 100 - 95[/tex]

                  [tex]\alpha = 5 \%[/tex]

                 [tex]\alpha =0.05[/tex]

Next we will obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table , the value is  [tex]Z_{\frac{\alpha }{2} } = 1.96[/tex]

Generally the sample size is mathematically represented as

           [tex]n = [\frac{Z_{\frac{\alpha }{2} * \sigma }}{ E} ]^2[/tex]

substituting values

             [tex]n = [\frac{1.96 * 0.5 }{ 0.1} ]^2[/tex]

            [tex]n =96[/tex]

The answer to the second question is  no the validity is null this because from the question we are told that the experiment require  one pH reading per rainfall so getting multiply specimens(used for the  pH reading) from  one rainfall will make the experiment invalid