One ingot contains 10 kg of pure silver and 2 kg of league. What quantity of silver, whose grade is 0.700; is it necessary to melt to obtain silver with a grade of 0.750?
a) 20
b) 22
c) 16
d) 24
e) 19

Answer:

Speed of plane in still air is 270 mph

Wind speed is 30 mph

Step-by-step explanation:

Check the picture.

The speed of the plane in still air is 270 mph and the speed of the wind will be 30 mph.

The distance traveled by an object is the product of the speed of an object and the time taken.

Distance = speed x time

An airplane travels 1200 miles in 4 hours with the wind. The same trip takes 5 hours against the wind.

Let the speed of the plane be x

The speed of wind be y

Distance covered with the wind = (x + y)t

                  1200   =  (x + y)4

                   (x + y) = 1200/4

                     (x + y)= 300       .....(a)

Distance covered against the wind = (x - y)t

                                              1200   =  (x - y)5

                                               (x - y) = 1200/5

                                                 (x - y) = 240         .......(b)

By solving both the equation

(x + y)= 300    

(x - y) = 240    

Therefore the values will be x= 270mph and  y = 30 mph

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Answer:

Brainliest!

Step-by-step explanation:

36x^-4y^2/5x^2y^-3z^-2

36y^5z^2/5x^6

make everything positive

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.

Answer:

14 + 25l + 6l^2

Step-by-step explanation:

(7 + 2i) (2 + 3i)

=> 14 + 4l + 21l + 6l^2

=> 14 + 25l + 6l^2

This is the correct answer

Answer:

A Maybe

Step-by-step explanation:

Cogntive identification

Unable to answer mathematically or analytically

The Plan of the solid shape is shown by : (A)

A solid shape can be defined as a shape that possesses three dimensions. that is to say they are three dimensional shapes.

A solid shape has both length, width and height. They are more tangible and look physical than two dimensional shape.

solid shapes can take up space in the universe because they are more tangible and realistic.

In conclusion, the Plan of the solid shape is shown by : (A)

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Answer:

6.5

Step-by-step explanation:

The sum of all angles in a triangle are 180 degrees.

=> 10x -10 + 8x + 10x + 8 = 180

=> 28x -2 = 180

=> 28x = 182

=> x = 6.5

So, Angle A = 10 x 6.5 -10 = 65 - 10 = 55 degrees

     Angle B = 8 x 6.5 = 52 degrees

     Angle C = 10 x 6.5 + 8 = 65 + 8 = 73 degrees.

55 + 52 + 73 = 55 + 125 = 180 degrees

Answer:

D

Step-by-step explanation:

The true statement is:

The functions f and g have the same axis of symmetry, and the y-intercept of f is greater than the y-intercept of g.

A mathematical phrase, rule, or law that establishes the link between an independent variable and a dependent variable (the dependent variable). In mathematics, functions exist everywhere, and they are crucial for constructing physical links in the sciences.

As, per the graph and table is:

From the graph of f(x):

Axis of symmetry will be at x = 2

The maximum value of f(x) = 10

From the table of g(x):

Axis of symmetry will be at x = 2

The minimum value of g(x) = 4

thus, The functions f and g have the same axis of symmetry, and the y-intercept of f is greater than the y-intercept of g.

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Answer:

Step-by-step explanation:

Answer:

8,8,-8,-8,8, ... is neither arithmetic nor geometric

Step-by-step explanation:

8,8,-8,-8,8, ...

This sequence is neither arithmetic nor geometric

We could also write

8,8,8,8,8, ... this is geometric since we multiply by 1 each time

Answer: hello below is the complete question

How many adults must be randomly selected to estimate the mean FICO (credit rating) score of working adults in a country? We want 90% confidence that the sample mean is within 4 points of the population mean, and the population standard deviation is 66. Round up to the nearest whole number

answer : 737 adults

Step-by-step explanation:

confidence interval = 90% = 0.9

( E ) = 4

standard deviation = 66

first we have to calculate the value of a

a = 1 - confidence interval

  = 1 - 0.9 = 0.10      hence  a / 2 = 0.05

next find the value of Z a/2 from table

Z[tex]_{0.05}[/tex]  = 1.645

The number of Adults selected can be determined using this relation

N = [tex](Z_{a/2} * (s/E))^2[/tex]

   = [tex](Z_{0.05} * ( 66/4))^2[/tex]

   = 737

Answer:

90

Step-by-step explanation:

Answer:

90

Step-by-step explanation:

Here is the equation

[tex]20+3\times(7+4)+5+2\times(7+9)[/tex]

In the order of operations parentheses go first so we get

[tex]20+3\times11+5+2\times16[/tex]

Next we do the multiplication

[tex]20+33+5+32\\[/tex]

And finally we add them all up

[tex]20+33+5+32=90\\[/tex]

Thus, 90 is the answer of [tex]20+3\times(7+4)+5+2\times(7+9)[/tex] or [tex]20+3(7+4)+5+2(7+9)[/tex]

Answer:

Step-by-step explanation:

Probability is the likelihood or chance that an event will occur.

Probability = Expected outcome of event/Total outcome.

If a video rental store keeps a list of their top 15 movie rentals each week, the total outcome is 15.

If the list for the week includes 6 action, 4 comedies, 3 dramas, and 2 mysteries and the store manager removes a copy of each of the 15 movies from the shelf, then randomly selects 3 of the 15 to show on the display monitors in the store, the probability that she selected 2 comedies and 1 action movie will be calculated as shown;

Probability of selecting 2 comedies  = 4/15*4/15 = 16/225 (Note that the expected outcome in this case is 4).

Probability of selecting 1 action movie = 6/15 = 2/5

Hence, the probability that she selected 2 comedies and 1 action movie will be equivalent to 16/225*2/5 = 32/1125

Note that the rented movies will have to be returned hence reason for the replacement.

Answer:

Step-by-step explanation:

Following the cardinal points as regards location of points, the sketch of Musah's movement can be as what is attached to this answer.

Answer:

(A) 0.11

(B) 0.0526

(C) Related

(D) 0.28

Step-by-step explanation:

The data provided is:

DC = event that a randomly selected driver is using a cell phone

TA = event that a randomly selected driver has a traffic accident

(A)

From the provided data:

P (DC) = 0.11

(B)

From the provided data:

P (TA) = 0.0526

(C)

To determine whether the events DC and TA are dependent, we need to show that:

[tex]P(DC\cap TA)\neq P(DC)\times P(TA)[/tex]

The value of P (DC ∩ TA) is,

[tex]P(DC\cap TA)=P(DC|TA)\time P(TA)[/tex]

                     [tex]=0.28\times 0.0526\\=0.014728[/tex]

Now compute the value of P (DC) × P (TA) as follows:

[tex]P (DC) \times P (TA)=0.11\times 0.0526=0.005786[/tex]

So, [tex]P(DC\cap TA)\neq P(DC)\times P(TA)[/tex]

Thus, cell phone use while driving and traffic accidents are related.

(D)

The probability that the driver was distracted by a cell phone given that the driver has an accident is:

P (DC | TA) = 0.28

Answer:

[tex]\text{Ratio as a fraction - \: \boxed{\frac{8}{18}}}[/tex]

[tex]\text{Fraction in simplest form - \boxed{\frac{4}{9}}}[/tex]

Step-by-step explanation:

Part 1: Writing a ratio as a fraction

A fraction and a ratio are the same thing - just a different name. Therefore, the colon in a ratio is the same as a divisor line in a fraction. Therefore, to write a ratio as a fraction,

Therefore, 8:18 as a fraction is 8/18.

Part 2: Fraction in simplest form

To put a fraction in simplest form, first divide the numerator by the denominator. If it contains a remainder, you cannot use this step to verify it.

8 only goes into 18 twice and leaves a 2 as a remainder, so this method does not work.

Instead, if both numbers are even, divide by 2.

8/2 = 4

18/2 = 9

Check to see if the new numerator and denominator can reduce any further.

4/9 = 4/9

The fraction in simplest form is 4/9.

Answer:

Approximately 3.05

Step-by-step explanation:

Using "compatible numbers" we can simply round these numbers to integer values.  Let's make 76.32 => 76 and 24.98 => 25

So from here let's do 76/25 to get 3 R 1/25

1/25 as a decimal is .04

So far, we have 3.04.  Going back to Look at our decimals, .32 and .98, there is a larger difference in our down rounding with the .32 than the up rounding from our .98.  So we should consider an extra value in our decimal.

Considering our whole number of 3.0, we can assume that our rounding will have an increase of about .01 or .015 in error.

Thus our number will be 3.04 + .01.

Making our quotient approximately 3.05.

Cheers.

Answer:

(C) A reflection across a horizontal line and a horizontal translation

Step-by-step explanation:

We can see that, near the x-axis, these shapes are 3 y values away from the x-axis, meaning that if we reflect one over the x-axis we will be at the same y values as the other shape.

Reflecting these points shows that we’ve got the same shape, just skewed the one side. We can then translate this shape horizontally to get it to where we want it.

Hope this helped!

Answer:

There are 80 10th graders in the school

Step-by-step explanation:

Let the number of 10th graders be x

There are 25% fewer 11th graders

That mean x - 25% of x

x -0.25x = 0.75x

There are 20% more 11th graders than 12th graders

So if number of 12th graders = y, then

0.75x = y + 20/100 * y = y + 0.2y = 1.2y

Since ;

0.75x = 1.2y

then y = 0.75x/1.2 = 0.625x

So let’s add all to give 190

x + 0.75x + 0.625x = 190

2.375x = 190

x = 190/2.375

x = 80

Answer:  6 seconds

Step-by-step explanation:

x refers to time. Since we want to know how long it is in the air, we need to find the time (x) when the ball lands on the ground (y = 0)

0 = -14x² + 84x

0 = -14x(x - 6)

0 = -14x     0 = x - 6

0 = x         6 = x

x = 0 seconds is when the ball was hit

x = 6 seconds is when the ball landed on the ground

Answer:

As the calculated value of t =2.1698 is greater than t (0.05,11) = 1.796 reject H0 . It means  chosen bottles stored for a month convince you that the mean furfuryl ether content exceeds the taste threshhold.

Step-by-step explanation:

We formulate our null and alternative hypotheses as

H0 u≤ 6 ug     Ha : u > 6 ug

The significance level ∝ = 0.05

The test statistic used is

t = X` - u / s/ √n

which if H0 is true, has the students' t test with n-1 = 11 degrees of freedom.

The critical region t > t (0.05,11) = 1.796

We compute the t value from the data

Xi               Xi²

8.92         79.5664

6.99          48.8601

5.54          30.6916

5.73           32.8329

6.38           40.7044

5.51            30.3601

6.45           41.6025

7.50           56.25

8.48           71.9104

5.56          30.9136

6.90          47.61

6.46          41.7316          

80.42         553.0336      

Now x` = ∑x/ n = 80.42/12 = 6.70

S²= 1/n-1 ( ∑(xi- x`)²= 1/11 ( 553.034 - (80.42)²/12)

= 1/11 (553.034-538.948) = 1.2805

s= 1.1316

Putting the values in the test statistics

t = X` - u / s/ √n = 6.70- 6 / 1.1316 / √12

= 2.1698

The critical region t > t (0.05,11) = 1.796

As the calculated value of t =2.1698 is greater than t (0.05,11) = 1.796 reject H0 . It means  chosen bottles stored for a month convince you that the mean furfuryl ether content exceeds the taste threshhold.

Answer:

Yes you can

Step-by-step explanation:

To eliminate the denominator

Answer:

No

Step-by-step explanation:

We cannot be certain that x + 3 > 0

If it was negative then the sign of the inequality would change.

To solve find the critical values of the numerator/ denominator, that is

x = 2 and x = - 3

The domain is the split into 3 intervals

(- ∞, - 3 ), (- 3, 2), (2, + ∞ )

Use test points from each interval to determine valid solution

Answer:

The  number is  [tex]N =1147[/tex] students

Step-by-step explanation:

From the question we are told that

    The population mean is  [tex]\mu = 281[/tex]

     The standard deviation is  [tex]\sigma = 34.4[/tex]

    The sample size is  n = 2000

percentage of the would you expect to have a score between 250 and 305 is mathematically represented as

      [tex]P(250 < X < 305 ) = P(\frac{ 250 - 281}{34.4 } < \frac{X - \mu }{\sigma } < \frac{ 305 - 281}{34.4 } )[/tex]

Generally  

             [tex]\frac{X - \mu }{\sigma } = Z (Standardized \ value \ of \ X )[/tex]

So  

         [tex]P(250 < X < 305 ) = P(-0.9012< Z<0.698 )[/tex]

       [tex]P(250 < X < 305 ) = P(z_2 < 0.698 ) - P(z_1 < -0.9012)[/tex]

From the z table  the value of  [tex]P( z_2 < 0.698) = 0.75741[/tex]

                                         and  [tex]P(z_1 < -0.9012) = 0.18374[/tex]

     [tex]P(250 < X < 305 ) = 0.75741 - 0.18374[/tex]

      [tex]P(250 < X < 305 ) = 0.57[/tex]

The  percentage is  [tex]P(250 < X < 305 ) = 57\%[/tex]

The  number of students that will get this score is

           [tex]N = 2000 * 0.57[/tex]

           [tex]N =1147[/tex]

Answer:

37°

This is because the square indicates a right angle.

53 - 90 = 37

We have,

Now,

AOB + ∠BOC = ∠A0C

⇒ 53° + x° = 90°

⇒ x° = 90° - 53°

⇒ x° = 37°

Answer:

In the error term.

Step-by-step explanation:

A simple linear regression is a regression that has only one explanatory variable. It tries to establish the existing relationship between the variable of interest (dependent variable) and the explanatory variable (independent variable).

Since age is the only explanatory variable, other variables such as faminc would be in the error term. The error term exists because the explanatory variable is never able to on its own to predict the dependent variable perfectly.

let [tex] \gcd(a,b)= G[/tex] , $a\ge b$

$\therefore a=G\cdot m$ and $b=G\cdot n$

$a-b=Gm-Gn=G(m-n)$

Now, $\gcd(a-b,b)$ clearly is, $G$

Answer:

Since x= 12 (0.006461) does not fall in the critical region so we accept our null hypothesis and conclude that the coin is fair.

Step-by-step explanation:

Let p be the probability of heads in a single toss of the coin. Then our null hypothesis that the coin is fair will be formulated as

H0 :p 0.5   against   Ha: p ≠ 0.5

The significance level is approximately 0.05

The test statistic to be used is number of heads x.

Critical Region: First we compute the probabilities associated with X the number of heads using the binomial distribution

Heads (x)        Probability (X=x)                        Cumulative     Decumulative

0                        1/16384 (1)             0.000061     0.000061

1                         1/16384  (14)         0.00085             0.000911

2                       1/16384 (91)           0.00555             0.006461

3                       1/16384(364)         0.02222

4                       1/16384(1001)         0.0611

5                       1/16384(2002)       0.122188

6                        1/16384(3003)      0.1833

7                         1/16384(3432)      0.2095

8                        1/16384(3003)       0.1833

9                        1/16384(2002)       0.122188

10                       1/16384(1001)        0.0611

11                       1/16384(364)        0.02222

12                      1/16384(91)            0.00555                             0.006461

13                     1/16384(14)              0.00085                           0.000911

14                       1/16384(1)            0.000061                            0.000061

We use the cumulative and decumulative column as the critical region is composed of two portions of area ( probability) one in each tail of the distribution. If  alpha = 0.05 then alpha by 2 - 0.025 ( area in each tail).

We observe that P (X≤2) =   0.006461 > 0.025

and

P ( X≥12 ) = 0.006461 > 0.025

Therefore true significance level is

∝=  P (X≤0)+P ( X≥14 ) = 0.000061+0.000061= 0.000122

Hence critical region is (X≤0) and ( X≥14)

Computation x= 12

Since x= 12 (0.006461) does not fall in the critical region so we accept our null hypothesis and conclude that the coin is fair.

Answer:

Left angle = 60°

Top angle = 120°

Right angle = 60°

Step-by-step explanation:

Use what you know about angle relationships to set up equations you can solve for each variable.

The top top angle, for example, added to one of the other angles must equal 180° because they are supplementary.

You have two variables, so you need at least two equations (I made three but only used two).

The work is in my attachment, comment of you have questions.

Answer:

C≈31.42

Step-by-step explanation:

C=2πr

C=2xπx5

C≈31.42

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