Two airplanes leave an airport at the same time, flying in the same direction. One plane is flying at twice the speed of the other. If after 4 hours they are 1800 km apart, find the speed of each plane.

Answer:

the area of the circle is 102.11 square metres

Answer:

28

Step-by-step explanation:

number of copies done in 5 minute 15 seconds = 147

60 seconds is equal to 1 minute

1 second is equal to 1/60 minutes

therefore 15 seconds is equal to 1/60 * 15 minutes = 1/4 minutes

thus,

number of copies done in 5 1/4 minute = 147

number of copies done in 1 minute = 147/ 5 1/4   (as 147/21 = 7)

                                                = 147/ (21/4) = 7*4 = 28

Thus, A copy machine makes 28 copies in 1 minute.

Answer:

17.85 feet.

Step-by-step explanation:

Area = 1/4 * 3.14 * r^2  where r is the radius

So r^2 = 19.625 / (1/4 * 3.14)

r^2 = 25

r = 5 feet.

The perimeter = 2r + 1/4 * 2* 3.14*r

= 2*5 + 7.85

= 17.85 feet.

Answer:

A=450

Step-by-step explanation:

A=a+b

2h=12+33

2·20=450

Answer:

Area=450

Step-by-step explanation:

[tex]a+b/2h[/tex]

Answer:

In the figure ∠ABO and ∠BCO have measures equal to 35°.

Step-by-step explanation:

Measure of arc AD = 180-measure of arc CD= 180-125 =55

m<AOB= 55 ( measure of central angle is equal to intercepted arc)

<OAB= 90 degrees (Tangent makes an angle of 90 degrees with the radius)

In triangle AOB ,

< AB0 = 180-(90+55)= 35 degrees( angle sum property of triangle)

In triange BOC ,< BOC=125 ,

m<, BCO=35 degrees

Answer:

∠ABO and ∠BCO

Step-by-step explanation:

Answer:

  a = (d -c)/b

Step-by-step explanation:

Undo the addition of c, by subtracting c.

  ab +c -c = d -c

  ab = d - c

Undo the multiplication by b, by dividing by b.

  ab/b = (d -c)/b

  a = (d -c)/b

Step-by-step explanation:

Find the lowest common multiple of 15 and 12.

Which is 60.

15×4=60 so 32x4=£1.28

12x5=60 so 43x5=£2.15

2.15+1.28= £3.43

Answer:

a) Median amount of time that is spent is around 2.3, rounded to 2.

b) 4 unit time

c) Mean amount of time is bigger than the median.

Step-by-step explanation:

Find the given attachment.

Note: Complete Question, along with the diagram is added

Answer:

It would be 27.328  but since it is money, we have to leave the 8 out.

So the answer is 27.32

Step-by-step explanation:

Answer:

$27.33

Step-by-step explanation:

You multiply 12.2 and 2.24 and the answer is 27.328. You then round it to the nearest tenth which is 27.33.

Answer:

36

Step-by-step explanation:

11*11=4

(1+1)*(1+1)=4

2 * 2 = 4

22*22=16

(2+2)*(2+2)=16

4 * 4 = 16

33*33=?

(3+3)*(3+3)=?

6 * 6 = 36

So the answer is 36

Series: 4, 16, 36

Answer: The answer is 36 :)

hope that helped

Answer:

(a)[tex]\dfrac{11}{26}[/tex]

(b)[tex]\dfrac{9}{13}[/tex]

(c)[tex]\dfrac{4}{13}[/tex]

Step-by-step explanation:

Number of cards in a Standard Deck=52

(a)

Number of Diamonds (D)=13

Number of Face Cards(F) = 12

Number of Diamonds that are face cards = 3

[tex]Pr($that the card is a diamond or a face card)=P(D)+P(F)-P(D \cap F)\\=\dfrac{13}{52} +\dfrac{12}{52} -\dfrac{3}{52} \\=\dfrac{22}{52} \\=\dfrac{11}{26}[/tex]

(b)The probability that the card is neither an ace nor a heart.

Number of Aces (A)=4

Number of Hearts(H) = 13

Number of Hearts that are Aces = 1

[tex]Pr($that the card is a Ace or a Heart), P(A \cup H)=P(A)+P(H)-P(A \cap H)\\=\dfrac{4}{52} +\dfrac{13}{52} -\dfrac{1}{52} \\=\dfrac{16}{52} \\$Therefore, probability that the card is neither an ace nor a heart.\\=1-P(A \cup H)\\=1-\dfrac{16}{52}\\=\dfrac{36}{52}\\=\dfrac{9}{13}[/tex]

(c)The probability that the card is a face card or a 3

Number of 3 cards(T)=4

Number of Face Cards(F) = 12

[tex]Pr($that the card is a three or a face card)=P(T)+P(F)\\=\dfrac{4}{52} +\dfrac{12}{52} \\=\dfrac{16}{52} \\=\dfrac{4}{13}[/tex]

Answer:

The common ratio is 4

Step-by-step explanation:

To find the common ratio take the second term and divide by the first term

-20/-5 = 4

To verify take the third term and divide by the second

-80/-20 = 4

The common ratio is 4

Answer:

4

Step-by-step explanation:

To find the common ratio, divide one term by the term before it.

-20 ÷ -5 = 4

-80 ÷ -20 = 4

Each number is multiplied by 4 to get to the next number.

I hope this helps :))

Answer:

68°

Step-by-step explanation:

Angle IJK is 112

Opposite angles of a quadrilateral inscribed in a circle add up to 180°

So

m<IHK = 180-112

m<IHK = 68°

Answer:  The correct answer is:  

_________________________  

The given "graph" in the bottom right, lowest corner

Step-by-step explanation:

_________________________

Note:  When there is only one (1) equation give for a graph;

          and/or:  only one (1)  "inequality given";  

         we  look for the symbol.

If the symbol is "not" an "equals" symbol (i.e. not an:  =  symbol) ;

 we check for the type of "inequality" symbol.

If there is a:  "less than" (<) ;  or a "greater than" (>) symbol;  the graph of the "inequality" will have "dashed lines" (since there will be a "boundary").

If there is an "inequality" that is a: "less than or equal to" (≤) ;

                                                 or a: "greater than or equal to" (≥) ;

       →   then there will be not be a dashed line when graphed;

          but rather—a "solid line" ;  since "less than or equal to" ;

          or "greater than or equal to" —is similar to:

          "up to AND including"; or: "lesser/fewer than AND including".).

 _________________________  

Note:  We are given the "inequality" :

            →   " y <  x²  + 4x  "  .

_________________________________

Note that we have a "less than" symbol (< ) ; so the graph will have a:

   "solid line" [and not a "dotted line".].

_________________________________

Note that all of the graphs among our 4 answer choices have "dotted lines".

Not that all values (all x and y coordinated) within the "shaded portion" of the corresponding graph are considered part of the graph.  

As such, given any point within the shaded part,  the x and y coordinates must match the inequality (i.e. the given inequality must be true when one puts in the "x-coordinate" and "y-coordinate" into the "given inequality" :

→   " y <  x²  + 4x "  .

_________________________

Likewise, we can take any point within the "white, unshaded" portion of any of the graph, and take the "x-coordinate" and "y-coordinate" of that point, and the inequality: →   " y <  x²  + 4x  "  ;  will not hold true when the "x-coordinate" and "y-coordinate" values of that point— are substituted into the "inequality".  

_________________________

{Note:  Answer is continued on images attached.}.

Wishing you the best!

Answer:

a. P(X>695)=0.026

b. P(X<485)=0.44

Step-by-step explanation:

The question is incomplete:

a. higher than 695 on the test.

b. at most 485 on the test.

We have a normal distribution with mean 500 and standard deviation of 100 for the test scores. We will use the z-scores to calculate the probabilties with the standard normal distribution table.

a. We want to calculate the probability that a randomly selected student scores higher than 695.

We calculate the z-score and then we calculate the probability:

[tex]z=\dfrac{X-\mu}{\sigma}=\dfrac{695-500}{100}=\dfrac{195}{100}=1.95\\\\\\P(X>695)=P(z>1.95)=0.026[/tex]

a. We want to calculate the probability that a randomly selected student scores at most 485.

We calculate the z-score and then we calculate the probability:

[tex]z=\dfrac{X-\mu}{\sigma}=\dfrac{485-500}{100}=\dfrac{-15}{100}=-0.15\\\\\\P(X<485)=P(z<-0.15)=0.44[/tex]

Answer:

4x -8 +4y

Step-by-step explanation:

Distribute

4(x – 2 + y)

4*x -4*2 +4*y

4x -8 +4y

Answer:

x = 20

Step-by-step explanation:

The sum of the three angles in the diagram is 180 degrees since they form a straight line

x + 100 + 3x = 180

Combine like terms

100 +4x = 180

Subtract 100 from each side

100+4x-100 =180-100

4x= 80

Divide each side by 4

4x/4 = 80/4

x = 20

Answer:  The correct answer is:  " 2x² " .

________________________________

Step-by-step explanation:

________________________________

We are asked:  "What is the sum of:  "x + x² + 2" and "x² − 2 − x" ?

Since we are to find the "sum" ;

  →  We are to "add" these 2 (two) expressions together:

     →     (x + x² + 2) +  (x² − 2 − x) ;

Note:  Let us rewrite the above, by adding the number "1" as a coefficient to:  the values "x" ; and "x² " ;  since there is an "implied coefficient of "1" ;

            → {since:  "any value" ; multiplied by "1"; results in that exact same value.}.

            →     (1x + 1x² + 2) +  (1x² − 2 − 1x) ;

Rewrite as:

             →     1x + 1x² + 2) +  (1x² − 2 − 1x) ;

Now, let us add the "coefficient" , "1" ; just before the expression:

             "(1x² − 2 − 1x)" ;  

         {since "any value", multiplied by "1" , equals that same value.}.

And rewrite the expression; as follows:

            →     (1x + 1x² + 2) +  1(1x² − 2 − 1x) ;

Now, let us consider the following part of the expression:

                     →  " +1(1x² − 2 − 1x) " ;

________________________________

Note the distributive property of multiplication:

   →  " a(b+c) = ab + ac " ;

and likewise:

   →  " a(b+c+d) = ab + ac + ad " .

________________________________

So; we have:

→  " +1(1x² − 2 − 1x) " ;

  = (+1 * 1x²)  +  (+1 *-2) + (+1*-1x) ;

  =       + 1x²    +    (-2)     +  (-1x) ;

  =       +1x²    −    2   −  1x  ;

  ↔    ( + 1x²  −  1x  −  2)

Now, bring down the "left-hand side of the expression:

1x + 1x² + 2 ;

and add the rest of the expression:

     →  1x  +  1x²  +  2  +   1x²  −  1x  −  2 ;

________________________________

Now, simplify by combining the "like terms" ; as follows:

   +1x² + 1x² = 2x²  ;

   +1x −  1x = 0 ;  

   + 2 −  2  = 0 ;

________________________________

The answer is: " 2x² " .

________________________________

Hope this is helpful to you!

   Best wishes!

________________________________

Answer:

The correct answer is:  " 2x² " .

________________________________

Step-by-step explanation:

________________________________

We are asked:  "What is the sum of:  "x + x² + 2" and "x² − 2 − x" ?

Since we are to find the "sum" ;

 →  We are to "add" these 2 (two) expressions together:

    →     (x + x² + 2) +  (x² − 2 − x) ;

Note:  Let us rewrite the above, by adding the number "1" as a coefficient to:  the values "x" ; and "x² " ;  since there is an "implied coefficient of "1" ;

           → {since:  "any value" ; multiplied by "1"; results in that exact same value.}.

           →     (1x + 1x² + 2) +  (1x² − 2 − 1x) ;

Rewrite as:

            →     1x + 1x² + 2) +  (1x² − 2 − 1x) ;

Now, let us add the "coefficient" , "1" ; just before the expression:

            "(1x² − 2 − 1x)" ;  

        {since "any value", multiplied by "1" , equals that same value.}.

And rewrite the expression; as follows:

           →     (1x + 1x² + 2) +  1(1x² − 2 − 1x) ;

Now, let us consider the following part of the expression:

                    →  " +1(1x² − 2 − 1x) " ;

________________________________

Note the distributive property of multiplication:

  →  " a(b+c) = ab + ac " ;

and likewise:

  →  " a(b+c+d) = ab + ac + ad " .

________________________________

So; we have:

→  " +1(1x² − 2 − 1x) " ;

 = (+1 * 1x²)  +  (+1 *-2) + (+1*-1x) ;

 =       + 1x²    +    (-2)     +  (-1x) ;

 =       +1x²    −    2   −  1x  ;

 ↔    ( + 1x²  −  1x  −  2)

Now, bring down the "left-hand side of the expression:

1x + 1x² + 2 ;

and add the rest of the expression:

    →  1x  +  1x²  +  2  +   1x²  −  1x  −  2 ;

________________________________

Now, simplify by combining the "like terms" ; as follows:

  +1x² + 1x² = 2x²  ;

  +1x −  1x = 0 ;  

  + 2 −  2  = 0 ;

________________________________

The answer is: " 2x² " .

Step-by-step explanation:

Answer:

A.

Step-by-step explanation:

In the attached file

Answer:

27 stuffed bears

Step-by-step explanation:

Erin: 55   Su: 15

Erin: 55-7=48 ( 7 will be kept for herself)

Erin and her sisters: 48/4= 12

Each sister besides Erin and Su have 12

Su: 15+12=27

Thus, Su will have 27 stuffed bears

Answer:

31 Stuffed Bears

Step-by-step explanation:

55 - 7 = 48

48 / 3 = 16

16 + 15 = 31

Sue has 31 stuffed bears

Answer:

There were 210 downloads of the standard version.

Step-by-step explanation:

This question can be solved using a system of equations.

I am going to say that:

x is the number of downloads of the standard version.

y is the number of downloads of the high-quality version.

The size of the standard version is 2.6 megabytes (MB). The size of the high-quality version is 4.2 MB. The total size downloaded for the two versions was 4074 MB.

This means that:

[tex]2.6x + 4.2y = 4074[/tex]

Yesterday, the high-quality version was downloaded four times as often as the standard version.

This means that [tex]y = 4x[/tex]

How many downloads of the standard version were there?

This is x.

[tex]2.6x + 4.2y = 4074[/tex]

Since [tex]y = 4x[/tex]

[tex]2.6x + 4.2*4x = 4074[/tex]

[tex]19.4x = 4074[/tex]

[tex]x = \frac{4074}{19.4}[/tex]

[tex]x = 210[/tex]

There were 210 downloads of the standard version.

Answer:

3,380 combinations

Step-by-step explanation:

26*5*26= 3,380

Answer:

3380

Step-by-step explanation:

Since there are 26 letters, it would be

26*5*26

This is 3380

Answer:

9

Step-by-step explanation:

[tex]2x+3y=36\\\\2x+3(6)=36\\\\2x+18=36\\\\2x=18\\\\x=9[/tex]

Hope this helps!

Answer:

X= 9

Step-by-step explanation:

2x+3y=36

2x+3(6)=36

2x+18=36

    -18  -18

2x=18

----------

   2

x=9

Answer:

15 baskets

Step-by-step explanation:

Answer:

The box has sides of 11.07 cm and height of 3.69 cm.

The cost (minimum) is 147 cents per box.

Step-by-step explanation:

We have a box with open top, with a volume of 452 cm^3.

Let x: base side of the box, in cm, and y: height of the box, in cm.

Then, the volume can be expressed as:

[tex]V=x^2\cdot y=452\\\\y=452x^{-2}[/tex]

This box has 4 sides and 1 base. The material cost is 0.4 cents/cm^2 for the base and 0.6 cents/cm^2 for the sides.

Then, we can write the cost as:

[tex]C=0.4\cdot 1\cdot (x^2)+0.6\cdot 4\cdot (xy)\\\\\\xy=x\cdot(452x^{-2})=452x^{-1}\\\\\\C=0.4x^2+2.4(452x^{-1})\\\\\\C=0.4x^2+1084.8x^{-1}[/tex]

The value for x that gives a minimum cost can be found deriving the function C and equal to 0:

[tex]\dfrac{dC}{dx}=0.4(2x)+1084.8(-1\cdot x^{-2})=0\\\\\\0.8x-1084.8x^{-2}=0\\\\0.8x=1084.8x^{-2}\\\\0.8x^{1+2}=1084.8\\\\x^3=1084.8/0.8=1356\\\\x=\sqrt[3]{1356}\\\\x=11.07[/tex]

The height can be calculated with the equation:

[tex]y=452x^{-2}=452(11.07^{-2})=452\cdot 0.00816 =3.69[/tex]

The minimum cost can be calculated as:

[tex]C=0.4x^2+1084.8x^{-1}\\\\C(11.07)=0.4(11.07)^2+1084.8(11.07)^{-1}\\\\C(11.07)=0.4\cdot 122.51+1084.8\cdot0.09\\\\C(11.07)=49+98\\\\C(11.07)=147[/tex]

5×4=20 is closer to 24.9344.

[tex]487 \times 512=24.9344[/tex]

Let's try placing the decimals after the hundreds place.

[tex]4.87 \times 5.12=24.9344[/tex]

It works.

There is more than one possibility.

[tex].487 \times 51.2=24.9344[/tex]

[tex]48.7 \times .512=24.9344[/tex]

Answer:

[tex] 25.5 -3.3= 22.2[/tex]

[tex] 25.5 +3.3= 28.8[/tex]

And the confidence interval would be given by: [tex] 22.2\leq \mu \leq 28.8[/tex]

Step-by-step explanation:

[tex]\bar X=25.5[/tex] represent the sample mean for the sample  

ME= 3.3 represent the margin of error

Confidence interval

The confidence interval for the mean is given by the following formula:

[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex]   (1)

The margin of error is given by;

[tex] ME =t_{\alpha/2}\frac{s}{\sqrt{n}}= 3.3[/tex]

And the confidence interval would be given by:

[tex] 25.5 -3.3= 22.2[/tex]

[tex] 25.5 +3.3= 28.8[/tex]

And the confidence interval would be given by: [tex] 22.2\leq \mu \leq 28.8[/tex]

Answer:

The solution to the equation is (8,13).

Step-by-step explanation:

A linear system of equations is composed by two lines.

The solution of the system is the point where the two lines intersect, that is.

In this question:

Point of intersection (8,13).

So

The solution to the equation is (8,13).