An experienced teaching assistant can grade all exams for a calculus class 2 hours faster than a new teaching assistant. Working together, the teaching assistants can grade all the exams for the calculus class in 7 hours. How long would it take for the new teaching assistant to grade all of the exams for the calculus class alone?

Answers

Answer 1

Answer:

  15.07 hours

Step-by-step explanation:

The given relationship lets us write an equation in that uses rates in terms of tasks per hour. Let 'a' represent the number of hours it takes the assistant to grade exams alone. Then (a-2) is the number of hours it takes the experienced teacher. Working together, their total rate is ...

  1/a + 1/(a-2) = 1/7 . . . . . . . tasks per hour

  7(a -2) +7(a) = a(a -2) . . . . . multiply by 7a(a -2)

  14a -14 = a^2 -2a . . . . . . . eliminate parentheses

  a^2 -16a = -14 . . . . . . . . . subtract 14a

  a^2 -16a +65 = 50 . . . . add 64 to complete the square

  (a -8)^2 = 50 . . . . . . . write as a square

  a -8 = ±5√2 . . . . . . take the square root

  a = 8 +5√2 ≈ 15.072

It would take the teaching assistant about 15.07 hours to grade the exams alone.

_____

Additional comment

The quadratic also gives an extraneous solution of about 0.93 hours. This results in a negative task time for the experienced teacher. That solution makes no sense in the given scenario, so we ignored it.


Related Questions

5. Part A: Show another way to find the slope of the line that passes through the points listed in the table. Your way must be different from Avery's method.

. Part B: Justify why Avery's "divide y by x" method will not work to find the slope of every line and given an example (using a table, equation, or graph) in your justification

Answers

Answer:

The slope-intercept form

y = mx + b

Here m is the slope and b is y-intercept

When b= 0

y = mx

and

m = y/x

In this case Avery's method works

When b≠0

m = (y -b)/x

In this case Avery's method brings wrong outcome

Answer:

Step-by-step explanation:

A concrete truck loaded with concrete weighs up to 25 tons.
About how many pounds does the loaded truck weigh?
The loaded truck weighs
pounds.

Answers

Answer:

50,000 pounds

Step-by-step explanation:

1 ton = 2,000 pounds

How do I do this I’m stuck and I have no idea how to do this I’m very behind and need help

Answers

Ah, try downloading the math app guathmath, it might help

Step-by-step explanation:

I don't see all the options.

I only see the options under "angles", as it seems.

anyway, the way to prove this is :

the official definition of similar triangles is :

two triangles are said to be similar if their corresponding angles are congruent (and the corresponding sides are in proportion - but that is automatically true, when all 3 angles are matching).

so, if two pairs of corresponding angles in a pair of triangles are congruent, then the triangles are similar. we know this, because if two angle pairs are the same, then the third pair must also be equal (remember, the sum of all angles in a triangle is always 180°). When the three angle pairs are all equal, the three pairs of sides must also be in proportion.

now, we look at the 2 triangles.

the angles QPR and STR are congruent (the same size).

we know also the angles QRP and SRT : they are both 90° and therefore congruent.

and that means that also the third angles PQR and RST are equal and therefore congruent (due to the 180° sum rule).

so, we have all 3 pairs of angles to be congruent, and the two triangles are therefore similar.

The L.C.M of 16 and 18 is what? first person Brainliest answer​

Answers

Answer:

144 is the l.c.m of 16 and 18

explanation:

multiples:

16 - 16, 32, 48, 64, 80, 96, 112, 128, 144

18 - 18, 36, 54, 72, 90, 108, 126, 144

Therefore,  144 is the l.c.m of 16 and 18 which is divisible by both numbers.

Answer:

144

Step-by-step explanation:

First, prime factorize the numbers.

16 = 2⁴

18 = 3² x 2

LCM (16, 18) = 2⁴ x 3²

= 16 x 9

= 144

Solution :-

144

100cm to 1 km in simplest form​

Answers

Answer:

100cm = 0.001km

Step-by-step explanation:

100 divided by 100,000=0.001

Answer:

1/100th part of the whole part.

Step-by-step explanation:

Hope this helps :)

What is the GCF of 96 and 56??
A:14
B:2
C:8
D:16

Answers

Answer:

8

Step-by-step explanation:

ANSWER


answer is C. 8


STEP BY STEP EXAMPLE

Tanisha lives with her older sister and helps with the rent by paying $500 per month. Her annual salary as a child care specialist is $14,700 after taxes. Shopping is her favorite pasttime and loves buying new things, but she also wants to save money for her college classes. Select the budget that would best help meet her goals. Table A Monthly Budget Budget A Budget B Budget C Budget D Income $1,470 $1,225 $1,470 $1,225 Expenses - Rent Food.

Answers

Tanisha lives with her older sister and helps with the rent by paying $500 per month. Her annual salary as a child care specialist is $14,700 after taxes. So  to save money for her college classes her monthly budget should be less than 725 .

What is budget ?

Budget is total plan of income and expenditure of a period .

Here given that Her annual salary as a child care specialist is $14,700 after taxes. and she lives with her older sister and helps with the rent by paying $500 per month.

So money she have after rent can be calculated as:

[tex]14700-12\times500\\\\14700-6000\\\\=8700[/tex]

So her monthly saving after rent is

[tex]\frac{8700}{12} \\\\\\=725[/tex]

So her  monthly budget should be less than 725

Tanisha lives with her older sister and helps with the rent by paying $500 per month. Her annual salary as a child care specialist is $14,700 after taxes. So  to save money for her college classes her monthly budget should be less than 725 .

To learn more about budget visit :https://brainly.com/question/24940564

Answer:

B

Step-by-step explanation:

Edge 2022

have a great day!

L is the midpoint of MN¯¯¯¯¯¯¯, ML=2x+7 and LN=3x−3. Find ML, LN, and MN.

Answers

Answer:

[tex]ML=27\\LN=27\\MN=54[/tex]

Step-by-step explanation:

Since L is the midpoint of MN, by the definition of midpoint:

[tex]ML=LN[/tex]

We can picture the following segment:

M----------L----------N

We know that [tex]ML=2x+7[/tex] and [tex]LN=3x-3[/tex]. Since the two segments are equivalent, we can set them equal to each other:

[tex]2x+7=3x-3[/tex]

Now, let's solve for x. Subtract -7 from both sides:

[tex]2x=3x-10[/tex]

Subtract 3x from both sides:

[tex]-x=-10[/tex]

Divide both sides by -1:

[tex]x=10[/tex]

So, the value of x is 10.

With this, we can find the remaining lengths.

We know that ML is [tex]2x+7[/tex].

Substitute 10 for x. So, the length of ML is:

[tex]ML=2(10)+7=20+7=27[/tex]

We know that LN is [tex]3x-3[/tex]. So, the length of LN is:

[tex]LN=3(10)-3=30-3=27[/tex]

Finally, MN will be the combined lengths of ML and LN. So:

[tex]MN=ML+LN=27+27=54[/tex]

And we're done!

Answer:

jdjssusaudisjdssdIes

I’m slow at these stuff Please I’ll be so glad if someone help with this =^=

Answers

Answer:

the <5 = 28

because if u add <1 and <5 it will be a 180°

so....if u 180 - 152 ( which is the angle of 1< )

and

same goes to 2< and <3 but its a 90°

so....<2 = 90° - 36°

= 54

u should get the <4 too....

hope u get it

please mark me brilliant

what is the equation of the new line?

Answers

Answer:

y = 2/3x - 3

Step-by-step explanation:

Given equation :-

y = 2/3x + 2

Transformations :-

Shifted down 5 units⇒ Slope remains same, y-intercept decreases by 5

Solving :-

New equation ⇒ y = 2/3x + 2 - 5y = 2/3x - 3

The graph shows the distance cars A and B travel.
Which statement is true about the unit rates shown in the graph?

A. The unit rate for car A is greater because the slope is greater than the slope for car B.
B. The unit rate for car B is greater because the slope is less than the slope for car A.
C. The unit rate for car A is greater because the slope is less than the slope for car B.
D. The unit rate for car B is greater because the slope is greater than the slope for car A.

Answers

Answer:

(a) The unit rate for car B is greater because the slope is greater than the slope for car A.

Step-by-step explanation:

We have been given a graph that represents the distance cars A and B travel. We are asked to choose the correct option about our given graphs.

Since slope represents the change in y-value with respect to change in per unit x value, so slope is also unit rate of the graph.

Let us find the slope of car A using points (8,5) and (0,0).

Let us find the slope of car B using points (5,8) and (0,0).

We can see that slope of car B is greater than slope of car A, therefore, option A is the correct choice.

Step-by-step explanation:

what is the missing value of 8/40 = 12/n

Answers

Answer:

The answer is 60!


The diagram shows a tetrahedron.

AD is perpendicular to both AB and AC.

AB = 10 cm.

AC = 8 cm.

AD = 5 cm.

Angle BAC = 90°

Calculate the size of angle BDC.

Give your answer correct to 1 decimal place.​

Answers

Answer: Angle BDC = 76.3 degrees

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

Work Shown:

For now focus on triangle ABC. Since this is a right triangle, we can use the pythagorean theorem to find the hypotenuse BC.

a^2 + b^2 = c^2

(AC)^2 + (AB)^2 = (BC)^2

8^2 + 10^2 = (BC)^2

(BC)^2 = 164

BC = sqrt(164)

BC = 12.806248 approximately

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

Move onto triangle ABD. Find the missing side BD through the pythagorean theorem

a^2 + b^2 = c^2

(AD)^2 + (AB)^2 = (BD)^2

5^2 + 10^2 = (BD)^2

125 = (BD)^2

(BD)^2 = 125

BD = sqrt(125)

BD = 11.1803399 which is approximate

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

Move onto triangle ADC. We'll use the pythagorean theorem again

a^2 + b^2 = c^2

(AC)^2 + (AD)^2 = (CD)^2

8^2 + 5^2 = (CD)^2

89 = (CD)^2

(CD)^2 = 89

CD = sqrt(89)

CD = 9.433981 also approximate

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

Focus on triangle BCD. We have the following side lengths

BC = 12.806248 BD = 11.1803399CD = 9.433981

Let

side d be opposite angle D, so d = BC = 12.806248 side b be opposite angle B, so b = CD = 9.433981side c be opposite angle C, so c = BD = 11.1803399

Note the use of uppercase letters for angles and lowercase letters for side lengths.

We can then use the law of cosines to find the angle we're after

d^2 = b^2 + c^2 - 2*b*c*cos(D)

12.806248^2=9.433981^2+11.1803399^2-2*9.433981*11.1803399*cos(D)

163.999987837504=213.999997787893-210.950228380284*cos(D)

-210.950228380284*cos(D) = -50.000009950389

cos(D) = (-50.000009950389)/(-210.950228380284)

cos(D) = 0.237022781792173

cos(D) = arccos(0.237022781792173)

D = 76.2891111084541

D = 76.3

The size of the angle ∠BDC of the tetrahedron can be determined by

cosine rule.

The size of angle ∠BDC is approximately 71.1°

Reasons:

A tetrahedron is a pyramid with triangular faces.

By Pythagoras's theorem, we have;

[tex]\overline{DC}[/tex]² = [tex]\mathbf{\overline{AD}}[/tex]² + [tex]\mathbf{\overline{AC}}[/tex]²

∴ [tex]\overline{DC}[/tex]² = 8² + 5² = 89

[tex]\overline{DC}[/tex]² = 89

[tex]\overline{BC}[/tex]² = [tex]\overline{AB}[/tex]² + [tex]\overline{AC}[/tex]²

∴ [tex]\overline{BC}[/tex]² = 10² + 8² = 164

[tex]\overline{BC}[/tex]² = 164

[tex]\overline{DB}[/tex]² = [tex]\mathbf{\overline{AD}}[/tex]² + [tex]\mathbf{\overline{AB}}[/tex]²

[tex]\overline{DB}[/tex]² = 5² + 10² = 150

[tex]\overline{DB}[/tex]² = 150

By cosine rule, we have;

[tex]\overline{BC}[/tex]² = [tex]\overline{DB}[/tex]² + [tex]\overline{DC}[/tex]² - 2 ×  [tex]\mathbf{\overline{DB}}[/tex] × [tex]\mathbf{\overline{DC}}[/tex] × cos(∠BDC)

Therefore;

164 = 150 + 89 - 2 × √(150) × √(89) × cos(∠BDC)

2 × √(150) × √(89) × cos(∠BDC) = 150 + 89 - 164 = 75

[tex]cos( \angle BDC) = \mathbf{\dfrac{75}{2 \times \sqrt{150} \times \sqrt{89} }}[/tex]

[tex]\angle BDC = arccos \left(\dfrac{75}{2 \times \sqrt{150} \times \sqrt{89} } \right) \approx \mathbf{71.1 ^{\circ}}[/tex]

∠BDC ≈ 71.1°

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https://brainly.com/question/20839703

Jace walked a total distance of StartFraction 5 Over 6 EndFraction of a mile to school this week. If he walked the same distance each of the 5 days, how far did he walk each day?

Answers

He walks 5/6 of a mile each day.

Multiply the distance each day by the number of days:

5/6 x 5

When multiplying a fraction by a whole number, multiply the numerator ( top number) by the whole number and leave the denominator ( bottom number as is)

5/6 x 5 = (5 x5)/6 = 25/6 now rewrite as a proper fraction:

25/6 = 4 1/6 total miles.

Answer:

4 1/6 miles over the course of 5 days

Step-by-step explanation:

The radius of a circular pond is increasing at a constant rate, which can be modeled by the function , where t is time in months. The area of the pond is modeled by the function . The area of the pond with respect to time can be modeled by the composition . Which function represents the area with respect to time? A. B. C. D.

Answers

Answer:

B. A(r(t)) = 25πt²

Step-by-step explanation:

Find the completed question below

The radius of a circular pond is increasing at a constant rate, which can be modeled by the function r(t) = 5t where t is time in months. The area of the pond is modeled by the function A(r) = πr². The area of the pond with respect to time can be modeled by the composition . Which function represents the area with respect to time? A. B. C. D.

Given

A(t) = πr²

r(t) = 5t

We are to evaluate the composite expression A(r(t))

A(r(t)) = A(5t)

To get A(5t), we will replace r in A(t) with 5t and simplify as shown

A(5t) = π(5t)²

A(5t) = π(25t²)

A(5t) = 25πt²

A(r(t)) = 25πt²

Hence the composite expression A(r(t)) is 25πt²

Option B is correct.

Answer:

Step-by-step explanation:

B . Correct

5. Find three solutions of the equation (1 point)
y = 2x - 6

(-2.-10). (1.-4). (2. -1)
(-2,-10), (1.-4), (0.6)
(0.–6). (3.-2) (-2,-10)
(1.-4), (0.-6). (-1,-9)

Answers

The answer might be c. not 100% sure sorry

PLEASE HELP ill Mark BRAINLIEST 31 points too

Answers

Answer:(-1,7)

Step-by-step explanation:

What is the area of this figure?


Drag and drop the appropriate number into the box.


Please help!

Thank you! <3

Answers

Answer:

441

Step-by-step explanation:

I think

y =400(.99)x growth or delay?

Answers

Answer:

Delay

Step-by-step explanation:

Because you are multiply x into 0.99, every time the multiplication takes place it will only become 99% of the value of the product of x and 400.

find measure of w in this trapezoid *please help*

Answers

Answer:

34°

Step-by-step explanation:

sum interior measure = (n-1)*180 ; n is the number of sides

of the polygon

(n-1)*180

(4-2)*180

2*180

360° ( sum interior measure )

The angles of the quadrilateral are ( 90 , 90 , w , 146 )

90+90+146+w = 360

326+w = 360

w = 360-326

w = 34°

Hope you get benefit from it

i need for homework please answer

Answers

Answer:

well, they all give you answers as fractions,

A.=1/9

B.=1/64

C.=1/64

Step-by-step explanation:

Use the figure to complete a-d

Answers

a. absolute value

b. f(x) = |x-5|
when you shift left or right, you subtract the amount you’re moving from x inside the absolute value

c. f(x) = |x|-5
when you shift up or down, you add/subtract the amount you’re moving outside of the absolute value

d. shifted 4 units up

you can always plug in values for x and solve for y to check what the graph looks like if you’re stuck.

For what value of k does the equation have no solution? kx - 4 = 5x + 8

Answers

Answer:

Your answer is: k = 5+12/x

Isolate the variable by dividing each side by factors that don't contain the variable.

Step-by-step explanation:

Hope this helped : )

3. Which is NOT a way to write a ratio?

Answers

Answer:

Lowest term

Step-by-step explanation:

you can write a ratio using a fraction form, a colon form, and a word form. The lowest term is just a part of an answer.

How to find the angle measure x in the figures

Answers

Answer:

subtract 180 from the other two angles

Step-by-step explanation:

triangle involves 3 angles with x's in the equation, set the 3 angles = to 180 and solve

2 320 is invested for two years
at 14% p.a simple interest
At 12% p.a compound interest
which is a better investment and by how much

Answers

Answer:

which is a better investment and by how much

It's 14% p.a simple interest

Step-by-step explanation:

Simple interst:

Answer:

I = $ 649.60

Equation:

I = Prt

Calculation:

First, converting R percent to r a decimal

r = R/100 = 14%/100 = 0.14 per year,

then, solving our equation

I = 2320 × 0.14 × 2 = 649.6

I = $ 649.60

The simple interest accumulated

on a principal of $ 2,320.00

at a rate of 14% per year

for 2 years is $ 649.60.

Compound interest

Answer:

A = $2,945.78

A = P + I where

P (principal) = $2,320.00

I (interest) = $625.78

Calculation Steps:

First, convert R as a percent to r as a decimal

r = R/100

r = 12/100

r = 0.12 rate per year,

Then solve the equation for A

A = P(1 + r/n)nt

A = 2,320.00(1 + 0.12/12)(12)(2)

A = 2,320.00(1 + 0.01)(24)

A = $2,945.78

Summary:

(20 points) It has been suggested that the highest priority of retirees is travel. Thus, a study was conducted to investigate the differences in the

length of stay of a trip for pre- and post-retirees. A sample of 697 travelers were asked how long they stayed on a typical trip. The observed results

of the study are found below.

Answers

The expected frequencies from the data conducted to investigate the differences in the length of stay of a trip will be 221.7097, 72.471, 49.3881, and 25.7677.

How to calculate the expected frequencies?

From the complete question, the expected frequencies from the data about the trip will be calculated thus:

E(240) = (379 × 413) ÷ 706

=221.7097

E(83) =(379 × 153) ÷ 706

=72.471

E(40) = (379 × 92) ÷ 706

=49.3881

E(16) =(379 × 48) ÷ 706

=25.7677

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If a book rests on a flat table in what direction does the normal force from the table act on the book?

Answers

Answer:

The normal force is the force that a surface makes on an object that lies on that surface.

As the book rest flat in the table, the force acting on the book will be the gravitational force. This force pulls down the book against the table, then the normal force will be opposite to this, then the direction of this force is upwards. Being more exact, the normal force always acts on the normal direction to a given surface, to find the normal of a surface, you need to find the plane of the surface, then any perpendicular line to that surface will be "normal" to the surface (and the normal direction points away from the surface) then if the book is resting on top of the table, the direction of the normal will be upwards..

Then the force that acts on the book is normal to the surface of the table,

Hello people ~
factorise: p² - 13p - 30​

Answers

Answer:

[tex] {p}^{2} - 13p - 30 \\ \\ {p}^{2} - 15p - 2p - 30 \\ \\ p(p - 15) + 2(p - 15) \\ \\ (p + 2)(p - 15)[/tex]

# Jerry Don is here#

Answer:

[tex]\displaystyle [p + 2][p - 15][/tex]

Explanation:

Find two quantities that when differed to 13, they also multiply to 30. Those will be 2 and 15. The TINIER quantity gets the plus sign because the B-value is −13, therefore 15 gets the minus sign, leaving 2 with the plus sign.

I am joyous to assist you at any time.

HELP HELP HELPPPP question is in the Image pls help as soon as you can

Answers

Step-by-step explanation:

the answer is the last one, because if you plug in (5, -6) to both equations you would get equal answer.

Answer:

D

Step-by-step explanation:

5=x and -6=y so 5+-6 or 5-6=-1 so it makes the first equation true. Then plug it in to the second equation. (3)(5)--6 or (3)(5)+6 which = 15+6. 15+6=21. So both are true. Btw Im new to this hope this helps!

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