Pls help I don’t understand this one pls

Answer:

1 hour 56 minutes

Step-by-step explanation:

Given :

Time taken by Lucy = 3 hours 15 minutes = 3.25 hours

Time taken by brother = 4 hours 45 minutes = 4.75 hours

Rate = 1 / time taken

Lucy's rate = 1 / 3.25

Brother's rate = 1 / 4.75

Combined rate = Lucy's rate + brother's rate

Combined rate = 1/3.25 + 1/4.75

Combined rate = 0.5182186

Time taken if they work together = 1/ combined rate

= 1 / 0.5182186

= 1.9296 hours

= 1 hour (0.9296 * 60) minutes

= 1 hour 56 minutes (approximately)

Answer:

-5/16 or -0.3125

Step-by-step explanation:

Answer:

-11/12

Step-by-step explanation:

Fyi you can use the app photo math you just take a pic of the problem and it gives you the answer and explains the steps and it is free.

Answer:

The length that separates the top 8% is of 5.2162 centimeters, and the length that separates the bottom 8% is of 5.1038 centimeters.

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Mean of 5.16 centimeters and a standard deviation of 0.04 centimeters.

This means that [tex]\mu = 5.16, \sigma = 0.04[/tex]

Length that separates the top 8%

The 100 - 8 = 92th percentile, which is X when Z has a p-value of 0.92, so X when Z = 1.405.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.405 = \frac{X - 5.16}{0.04}[/tex]

[tex]X - 5.16 = 1.405*0.04[/tex]

[tex]X = 5.2162[/tex]

Length that separates the bottom 8%

This is the 8th percentile, which is X when Z has a p-value of 0.08, so X when Z = -1.405.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.405 = \frac{X - 5.16}{0.04}[/tex]

[tex]X - 5.16 = -1.405*0.04[/tex]

[tex]X = 5.1038[/tex]

The length that separates the top 8% is of 5.2162 centimeters, and the length that separates the bottom 8% is of 5.1038 centimeters.

Answer: Robert and Chris can skate 10 miles in 45 minutes.

Step-by-step explanation:

Let's start by finding the unit rate.

[tex]\frac{4}{18} =\frac{2}{9} \\\frac{18}{18} =1[/tex]

Robert and Chris can skate [tex]\frac{2}{9}[/tex] of a mile in 1 minute. Now we can multiply both by 45 to see how far the can go in 45 minutes.

[tex](\frac{2}{9}) (\frac{45}{1} )\\\frac{(2)(45)}{(9)(1)} \\\frac{90}{9} \\10[/tex]

45x1=45

The can skate 10 miles in 45 minutes.

The question is incomplete. The complete question is :

The population of a certain town was 10,000 in 1990. The rate of change of a population, measured in hundreds of people per year, is modeled by P prime of t equals two-hundred times e to the 0.02t power, where t is measured in years since 1990. Discuss the meaning of the integral from zero to twenty of P prime of t, d t. Calculate the change in population between 1995 and 2000. Do we have enough information to calculate the population in 2020? If so, what is the population in 2020?

Solution :

According to the question,

The rate of change of population is given as :

[tex]$\frac{dP(t)}{dt}=200e^{0.02t}$[/tex]  in 1990.

Now integrating,

[tex]$\int_0^{20}\frac{dP(t)}{dt}dt=\int_0^{20}200e^{0.02t} \ dt$[/tex]

                    [tex]$=\frac{200}{0.02}\left[e^{0.02(20)}-1\right]$[/tex]

                   [tex]$=10,000[e^{0.4}-1]$[/tex]

                    [tex]$=10,000[0.49]$[/tex]

                    =4900

[tex]$\frac{dP(t)}{dt}=200e^{0.02t}$[/tex]

[tex]$\int1.dP(t)=200e^{0.02t}dt$[/tex]

[tex]$P=\frac{200}{0.02}e^{0.02t}$[/tex]

[tex]$P=10,000e^{0.02t}$[/tex]

[tex]$P=P_0e^{kt}$[/tex]

This is initial population.

k is change in population.

So in 1995,

[tex]$P=P_0e^{kt}$[/tex]

   [tex]$=10,000e^{0.02(5)}$[/tex]

   [tex]$=11051$[/tex]

In 2000,

[tex]$P=10,000e^{0.02(10)}$[/tex]

   [tex]=12,214[/tex]

Therefore, the change in the population between 1995 and 2000 = 1,163.

Answer:

grade-point average (GPA).

Step-by-step explanation:

The Independent variable may be explained as the variable which is used to manipulate the variable to be predicted. The Independent variable also called the predictor variable takes up several input values in other to observe how the predicted variable changes due to this independent variable. In the scenario described above, the independent variable is the Grade - point average, as it is used to make prediction or manipulate the value of the starting salary earned by a graduate. The starting salary earned is the predicted variable or dependent variable in this scenario.

Answer:

2b^2

Step-by-step explanation:

according to the question equation is

(a^2 + b^2 ) - (a^2 - b^2)

a^2 + b^2 - a^2 + b^2

plus a square and minus a square gets cancel

b^2 + b^2

since they are like terms they can be added

2b^2

Answer:

2b^2

Step-by-step explanation:

according to the question equation is

(a^2 + b^2 ) - (a^2 - b^2)

a^2 + b^2 - a^2 + b^2

= b^2 + b^2

like terms can be added

+2b^2

Answer:

16

Step-by-step explanation:

baámmáy tính  

Answer:

this probability is 0.68

Step-by-step explanation:

the probability she buys fruit but not a CD is

0.6 × (1 - 0.2) = 0.48

the probability she buys a CD by not fruit is

0.2 × (1 - 0.6) = 0.08

the probability that she buys both is

0.6 × 0.2 = 0.12

the probability that she buys fruit or a CD or both is adding all 3 probabilities :

0.48 + 0.08 + 0.12 = 0.68

Answer:

d = 52°

Step-by-step explanation:

The two sides with little marks are congruent.

That means that the opposite angles are congruent.

One angle measures 76°.

The other to angles measure d each.

d + d + 76 = 180

2d + 76 = 180

2d = 104

d = 52

Answer: Read it to him again, and explain all the steps to him nice and slowly.

Answer:

2.5

Step-by-step explanation:

5/8 ÷ 1/4

Division sign changes to multiplication and the reciprocal of the divisior is used to multiply instead :

5/8 * 4/1

= (5*4) / (8*1)

= 20 / 8

= 2.5

Answer:

-1 over 2

Step-by-step explanation:

Answer:

-1/2

Step-by-step explanation:

The line joins (-2, 2) and (0, 1).

Remember that slope equals change in y all divided by the change in x.

Here,

change in y = 1 - 2 =- 1

change in x = 0 -(-2) = 2

Thus, slope =- 1/2

Answer:

option B : 31.4 cm

Step-by-step explanation:

Given radius , r = 5cm

Circumference = [tex]2 \pi r[/tex]

                       = 2 x 3.14 x 5

                       =10 x 3.14

                       = 31.4 cm

Answer:

b. 31.4

Step-by-step explanation:

The radius of the circle can be plugged into C=(pi)2r. So 5x2= 10 and 10x(pi)= 31.4

Answer:

I. m = 2401

II. ((n+1) ∆ y)/n = 1/n[(n – y + 2)(n – y) + 1]

Step-by-step explanation:

I. Determination of m

x ∆ y = x² − 2xy + y²

2 ∆ − 5 = √m

2² − 2(2 × –5) + (–5)² = √m

4 – 2(–10) + 25 = √m

4 + 20 + 25 = √m

49 = √m

Take the square of both side

49² = m

2401 = m

m = 2401

II. Simplify ((n+1) ∆ y)/n

We'll begin by obtaining (n+1) ∆ y. This can be obtained as follow:

x ∆ y = x² − 2xy + y²

(n+1) ∆ y = (n+1)² – 2(n+1)y + y²

(n+1) ∆ y = n² + 2n + 1 – 2ny – 2y + y²

(n+1) ∆ y = n² + 2n – 2ny – 2y + y² + 1

(n+1) ∆ y = n² – 2ny + y² + 2n – 2y + 1

(n+1) ∆ y = n² – ny – ny + y² + 2n – 2y + 1

(n+1) ∆ y = n(n – y) – y(n – y) + 2(n – y) + 1

(n+1) ∆ y = (n – y + 2)(n – y) + 1

((n+1) ∆ y)/n = [(n – y + 2)(n – y) + 1] / n

((n+1) ∆ y)/n = 1/n[(n – y + 2)(n – y) + 1]

Answer:

TRUE

Step-by-step explanation:

Those lines around the -5 mean the absolute value of the number, basically the value of the number without any negative signs. SO the absolute value of -5 is just 5.

5 IS GREATER than 3, so this is true

ur welcome :)

Answer:

Thw sum of 1/4 and 1/2 is 3/4

Step-by-step explanation:

You have to put them in common like terms so

1/4 + 1/2 = ?

1/4 + 2/4 = 3/4

1/4 + 1/2

(1 + 1*2)/4

3/4

I hope it's help you...

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Given:

Number of color pens Tracy have = 63

Number of color pens Jacob have = 46

To find:

How many more colors pens does Tracy have than Jacob​?

Solution:

We need to find the difference between the number of color pens Tracy have and the number of color pens Jacob have.

[tex]Difference=63-46[/tex]

[tex]Difference=17[/tex]

Therefore, Tracy have 17 more color pens than Jacob.

Answer:

0

Step-by-step explanation:

If you are looking for the x- intercept image is below

if you are looking for the y- intercept its the same as the x. Image is below

Answer:

[tex]h(x) = \frac {3}{2}x + 1 \\ { \tt{let \: the \: inverse \: be \: { \bold{m}}}} \\ { \tt{m = \frac{1}{ \frac{3}{2}x + 1 } }} \\ \\ { \tt{m = \frac{2}{3x + 2} }} \\ \\ { \tt{m(3x + 2) = 2}} \\ \\ { \tt{3x + 2 = \frac{2}{m} }} \\ \\ { \tt{x = \frac{2 - 2m}{3m} }} \\ \\ { \tt{x = \frac{2}{3m}(1 - m) }} \\ \\ { \bf{h {}^{ - 1} (x) = \frac{2}{3x}(1 - x) }}[/tex]

Answer:

C

Step-by-step explanation:  

Answer:

The agency makes 16110

The agent makes 3222

Step-by-step explanation:

First find the real estate commission

358000 * 4.5%

358000*.045

16110

The agent gets 20 percent of that amount

16110*20%

16110*.2

3222

Answer:

242 m³ of space is there in the fort.

Step-by-step explanation:

Given that,

The dimensions of first box is 4 meters long, 8 meters wide, and 8 meters high.

The dimensions of the second box is 2 meters long, 7 meters wide, and 1 meter high.

Space left = Volume of first box - volume of second box

= (4)(8)(8) - 2(7)(1)

= 242 m³

So, 242 m³ of space is there in the fort.

Step-by-step explanation:

Using an online calculator, I was able to find that one pattern is

[tex]a_{n} = a_{n-1} + 14 * 3^{n-1}[/tex] . Finding a recursive sequence is generally based on guess and check, so there isn't much explanation to obtaining one

Answer:

(s/t)(100%)

Step-by-step explanation:

Represent salaries by s and total expenses by t.  Then the fraction of total expenses allocated to salary is

  s

------

  t

and so the percentage of total expenses which is allocated to salary is

(s/t)(100%)

Here,

we have to determine the percentage of total expenses which is allocated to salary.

Let,

The percentage of total expenses allocated to salary is,

Answer:

Newton's law of cooling says that:

T(t) = Tₐ + (T₀ - Tₐ)*e^(k*t)

or:

[tex]\frac{dT}{dt} = -k*(T - T_a)[/tex]

in the differential form.

where:

T is the temperature as a function of time

Tₐ  is the ambient temperature, in this case, 70F

T₀ is the initial temperature of the object, in this case, 150F

k is a constant, and we want to find the value of k.

Then our equation is:

T = 70F + (150F - 70F)*e^(k*t)

Now we also know that after a minute, or 60 seconds, the temperature was 135F

then:

135F = 70F + (150F - 70F)*e^(k*60s)

We can solve this for k:

135F = 70F + 80F*e^(k*60s)

135F - 70F = 80F*e^(k*60s)

65F =  80F*e^(k*60s)

(65/80) = e^(k*60s)

Now we can apply the Ln(x) function to both sides to get:

Ln(65/80) = Ln(e^(k*60s))

Ln(65/80) = k*60s

Ln(65/80)/60s = k = -0.0035 s^-1

Then the differential equation is:

[tex]\frac{dT}{dt} = -0.0035 s^-1*(T - 70F)[/tex]

Option B is correct, the value of tan 74° is 24/7

Trigonometry is a branch of mathematics that studies relationships between side lengths and angles of triangles.

We have to find the value of tan74°

The tan function is ratio of opposite side and adjacent side.

We have to find the opposite side of angle 74°,

The opposite side has length 24

Now let us find the adjacent side of angle 74 which is 7

tan 74° = 24/7

Hence, option B is correct, the value of tan 74° is 24/7.

To learn more on trigonometry click:

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