What is the concentration of a new solution obtained by mixing 25ml of water with 125ml of a 20% salt solution in water?

Final answer:

It takes about 20 minutes to grade one student's paper, so for a class of 25 students, it would take a total of 500 minutes, which is approximately 8.33 hours to grade all the papers.

Explanation:

If it takes about 20 minutes to grade a student paper, to find out how long it takes to grade papers for a class of 25 students, we need to multiply the number of students by the time taken to grade each paper.

Step-by-Step Calculation:

Multiply the number of students (25) by the minutes per paper (20 minutes): 25 students * 20 minutes per student = 500 minutes.

Convert minutes to hours. Since there are 60 minutes in an hour, we'll divide the total minutes by 60: 500 minutes ÷ 60 minutes per hour = 8.33 hours.

Therefore, it takes approximately 8.33 hours to grade papers for a class of 25 students. Please note that this is an ideal situation without any breaks or interruptions accounted for.

Answer:

No solution.

Step-by-step explanation:

Use elimination.

Multiply the equation by the opposite equation's x coefficient.

9(-3x - 2y = -12)  =  -27x - 18y = -108

Again, multiply by the other x coefficient.

-3(9x + 6y = -9)  =  -27x - 18y = 27

Add the second equation to the first.

-27x - 18y = -108

+27x + 18y = -27  The x and y will cancel each other out.

0 ≠ 135. Since 0 does not equal 135, there is no solution.

Elimination gives an equation that is always false. The two equations in the system represent parallel lines. This is an inconsistent system. It has no solutions.

Answer:

1/2     -2

Step-by-step explanation:

The solution of 2x² + x − 4 = 0 is x = ( -1 ± √33 ) / 2.

A quadratic equation is what can be written in the form of ax²+bx+c=0

The equation is,

2x² + x − 4 = 0

To solve the equation, the equation needs to be factorized.

It can be also solved using the formula for determining roots.

x = ( -b ± √ (b² -4ac)) / 2a

Comparing it with the standard equation ax²+bx+c=0.

a = 2, b = 1, c = -4

Substituting the values

x = ( -1 ± √ (1² -4*2*-4)) / 2 * 2

x =  ( -1 ± √ (1 + 32)) / 2 * 2

x = ( -1 ± √33 ) / 2

The solution of the given quadratic equation is x = ( -1 ± √33 ) / 2.

To know more about Quadratic Equation

https://brainly.com/question/2263981

#SPJ6

The Cartesian plane is where an ordered pair of real numbers can be represented in a rectangular coordinate system.

In a rectangular (Cartesian) coordinate system, an ordered pair of real numbers can be represented in the Cartesian plane. The Cartesian plane is formed by the xy plane, where the x and y axes are perpendicular and intersect at the origin.

sqrt(1610) = 40.12 = -40.2

sqrt(680) = 36.08 = -36.08

sqrt(410) = 20.25 = -20.25

sqrt(27) = 5.20 = -5.20

is that supposed to be 025 or negative 25?

 the way the question is written

 the answer is C & D

The solution of the equation "[tex]x(x+2)+3(x+2)[/tex]" will be "[tex]5(x+3)[/tex]".

According to the question,

and,

By substituting "5" in place of "(x+2)" in the above given equation i.e.,

[tex]x(x+2)+3(x+2)[/tex], we get

= [tex]x(x+2)+3(x+2)[/tex]

= [tex]x(5)+3(5)[/tex]

By applying multiplication, we get

= [tex]5x+15[/tex]

= [tex]5(x+3)[/tex]

Thus the response above is appropriate.

Learn more:

https://brainly.com/question/18508632

Answer with explanation:

We have to find that expression , which has an estimated product of

1.→44.7 x 2.1

2.→7.5 x 8.4

3.→8.7 x 5.28

4.→38.1 x 7.3

We will start from option 1.

→44.7 x 2.1

44.7 when estimated to nearest tenth=45

2.1, when estimated to nearest tenth=2

44.7 × 2.1=45×2=90

Option 2

7.5 x 8.4

7.5 when estimated to nearest tenth=8

8.4, when estimated to nearest tenth=8

⇒7.5 × 8.4=8×8=64

Option 3

8.7 × 5.28

8.7, when estimated to nearest tenth=9

5.28, when estimated to nearest tenth=5

⇒8.7 × 5.28=9×5=45

Option D

38.1 × 7.3

38.1 when estimated to nearest tenth=38

7.3, when estimated to nearest tenth=7

⇒38×7=266

Option C:⇒8.7 × 5.28 has an estimated product of 45

Answer: f (g (-2)) = 25

Step-by-step explanation:

Hi, to evaluate (f ∘ g)(−2). Where:

f(x) = x2  

g(x) = x − 3

As (f ∘ g)(−2) = f (g (-2))  

First we find the value of g (-2) replacing the variable x by the number -2.

g (-2) =-2-3 = -5

Finally , for f(x) = x²,we replace the variable x for the value obtained (-5)

f (g (-2)) = (-5)²= 25

Feel free to ask for more if needed or if you did not understand something.

Answer:

x=16, y=-41

Step-by-step explanation:

The probability of first picks the red and then blue will be,15/121.

The chances of an event occurring are defined by probability. Probability has several uses in games, in business to create probability-based forecasts,

No of red marbles =3

No of white marbles = 3

No of blue marbles =5

Total no of the marble is;

T= 3+3+5=11

The probability of picking a red ;

[tex]\rm P_{red}=\frac{3}{11}[/tex]

The probability that the next pick will be blue is;

[tex]P_{( blue})=\frac{5}{11}[/tex]

P(red then blue) is;

[tex]P_{(red \rightarrow blue})=\frac{3}{11} \times \frac{5}{11} \\\\ P_{(red \rightarrow blue})=\frac{15}{121}[/tex]

Hence,the probability of first picks the red and then blue will be,15/121.

To learn more about the probability, refer to the link;

https://brainly.com/question/11234923

#SPJ2

The measure of m<OAC is 45degrees

From the given diagram, we can see that the line A is tangential to the circle at point C, hence m<C = 90 degrees

Taking the sum of angle in a triangle

m<OAC + 45 + 90 = 180

m<OAC = 180 - 135

m<OAC = 45 degrees

Hence the measure of m<OAC is 45degrees

Learn more on circle geometry here: https://brainly.com/question/25306774

Answer:

[tex]y=x^2+16x+64[/tex]

Step-by-step explanation:

A quadratic needs 2 solutions, but since you only have 1, I am to assume that x = -8 twice (or multiplicity of 2).  If x = -8, then in factor form, it's (x + 8).  Muliplying that by itself twice:

(x + 8)(x + 8):

[tex]x^2+8x+8x+64=0[/tex]

Simplifying gives you:

[tex]x^2+16x+64=y[/tex]

The required number of tokens distributed in each of them is 46 tokens.

In mathematics, it deals with numbers of operations according to the statements. There are four major arithmetic operators, addition, subtraction, multiplication and division,

Here,
Total money = 9 + 10 + 13 + 13 = $45
Total number of persons = 4
For the first $1 there are 8 token
And after that cost of 4 tokens is $1,
Total tokens = 8×1 + 4×(45 - 1)
Total tokens = 8 + 176
Total tokens = 184
Now,
Distribution among the fours,
= 184 / 4
= 46 tokens

Thus, the required number of tokens distributed in each of them is 46 tokens.

Learn more about arithmetic here:

https://brainly.com/question/11424589

#SPJ5

The answer is B.) $162.00

Given:

Volleyball (sphere) volume[tex]=\bold{\frac{4}{3} \pi r^2}[/tex]

[tex]\to \bold{r=11.44\ cm}[/tex]

putting the value into the formula:

[tex]=\bold{\frac{4}{3} \times 3.14 \times 11.4^2}\\\\=\bold{\frac{4}{3} \times 3.14 \times 1481.544}\\\\=\bold{\frac{4}{3} \times 4652.04816}\\\\=\bold{4 \times 1550.68272}\\\\=\bold{6202.73}\\\\[/tex]

The final volume of volleyball (sphere) "[tex]\bold{6202.73\ cm^3}[/tex]".

Learn more:

brainly.com/question/10245241

To find the volume of a volleyball with a radius of 11.4 cm, we plug the radius into the formula for the volume of a sphere, V=4/3(pi)(r^3), resulting in an approximate volume of 6185.7 cubic centimeters.

The question asks to evaluate the volume of a sphere using the given formula, which is V=4/3(pi)(r^3), where V represents the volume and r is the radius of the sphere. To find the volume of a volleyball with a radius of 11.4 cm, we substitute r with 11.4 in the formula and calculate the volume accordingly.

The calculation would be:

V = 4/3 × pi × (11.4 cm)^3
V = 4/3 × 3.14159 × 11.4 cm × 11.4 cm × 11.4 cm
V = 4/3 × 3.14159 × 1481.784 cm^3
V ≈ 4/3 × 3.14159 × 1481.784 cm^3
V ≈ 6185.7 cm^3

Therefore, the volume of the volleyball is approximately 6185.7 cubic centimeters.