My daughter had a quiz today and the 3 questions did not make sense to me. Can anyone decifer how you would solve for the variable on these? I am stumped!!

1) In 10 years, Sara will be 81 older than she is now. How old is Sara now?

2) In 8 years, Sara will be 49 years older than she is now. How old is Sara now?

3) In 11 years, Bob will be 100 years than he is now. How old is Bob now?

Answer:

5 Minutes

take 10 and add 12 for each minute until you pass 60

Answer:

a) The expression for the number of bacteria is [tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex].

b) There are 2975 bacteria after 3 hours.

c) The rate of growth after 3 hours is about 3365.3 bacteria per hour.

d) A population of 10,000 will be reached after 4.072 hours.

Step-by-step explanation:

a) The population growth of the bacteria culture is described by this ordinary differential equation:

[tex]\frac{dP}{dt} = k\cdot P[/tex] (1)

Where:

[tex]k[/tex] - Rate of proportionality, in [tex]\frac{1}{h}[/tex].

[tex]P[/tex] - Population of the bacteria culture, no unit.

[tex]t[/tex] - Time, in hours.

The solution of this differential equation is:

[tex]P(t) = P_{o}\cdot e^{k\cdot t}[/tex] (2)

Where:

[tex]P_{o}[/tex] - Initial population, no unit.

[tex]P(t)[/tex] - Current population, no unit.

If we know that [tex]P_{o} = 100[/tex], [tex]t = 1\,h[/tex] and [tex]P(t) = 310[/tex], then the rate of proportionality is:

[tex]P(t) = P_{o}\cdot e^{k\cdot t}[/tex]

[tex]\frac{P(t)}{P_{o}} = e^{k\cdot t}[/tex]

[tex]k\cdot t = \ln \frac{P(t)}{P_{o}}[/tex]

[tex]k = \frac{1}{t}\cdot \ln \frac{P(t)}{P_{o}}[/tex]

[tex]k = \frac{1}{1}\cdot \ln \frac{310}{100}[/tex]

[tex]k\approx 1.131\,\frac{1}{h}[/tex]

Hence, the expression for the number of bacteria is [tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex].

b) If we know that [tex]t = 3\,h[/tex], then the number of bacteria is:

[tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex]

[tex]P(3) = 100\cdot e^{1.131\cdot (3)}[/tex]

[tex]P(3) \approx 2975.508[/tex]

There are 2975 bacteria after 3 hours.

c) The rate of growth of the population is represented by (1):

[tex]\frac{dP}{dt} = k\cdot P[/tex]

If we know that [tex]k\approx 1.131\,\frac{1}{h}[/tex] and [tex]P \approx 2975.508[/tex], then the rate of growth after 3 hours:

[tex]\frac{dP}{dt} = \left(1.131\,\frac{1}{h} \right)\cdot (2975.508)[/tex]

[tex]\frac{dP}{dt} = 3365.3\,\frac{1}{h}[/tex]

The rate of growth after 3 hours is about 3365.3 bacteria per hour.

d) If we know that [tex]P(t) = 10000[/tex], then the time associated with the size of the bacteria culture is:

[tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex]

[tex]10000 = 100\cdot e^{1.131\cdot t}[/tex]

[tex]100 = e^{1.131\cdot t}[/tex]

[tex]\ln 100 = 1.131\cdot t[/tex]

[tex]t = \frac{\ln 100}{1.131}[/tex]

[tex]t \approx 4.072\,h[/tex]

A population of 10,000 will be reached after 4.072 hours.

Answer:

$325

Step-by-step explanation:

Find the regular price by dividing 247 by 0.76:

247/0.76:

= 325

So, the regular price was $325

Answer:

240

Step-by-step explanation:

minus how much u sold them and how much it cost to make

3-1=2

times 2 and 120

2(120)

240

Answer:

6.

Step-by-step explanation:

.

Answer:

[tex]C)\:8[/tex]

8 units tiles must be added

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~HOPE IT HELPS~

~HAVE A GREAT DAY!!~

Answer:

0.38 = 38% probability that it is neither red nor blue​.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

In this question:

100 cars.

Of those, 28 + 34 = 62 are either blue or red.

100 - 62 = 38 are neither blue of red.

What is the probability that it is neither red nor blue​?

38 out of 100, so:

[tex]p = \frac{38}{100} = 0.38[/tex]

0.38 = 38% probability that it is neither red nor blue​.

Answer:

9a²b

Step-by-step explanation:

Hi there!

We need to find the greatest common factor out of 45a²b³ and 18[tex]a^{4}[/tex]b

We can split apart the monomials to make it easier

45a²b³ is 45*a²b³

18[tex]a^{4}[/tex]b is 18*[tex]a^{4}[/tex]b

First, let's find the GCF out of 45 and 18 (the number coefficients)

we can find all of the multiples of the 2 numbers:

45 is made up of 9 and 5

9 is made up of 3 and 3

so 3*3*5 is 45

18 is made up of 2 and 9

9 is made up of 3 and 3

so 2*3*3 is 18

3*3 is in both 45 and 18, so 9 is the GCF out of 45 and 18

Now let's find the GCF out of a²b³ and [tex]a^{4}[/tex]b

a²b³ made up of a² and b³

so a²b³ is a*a*b*b*b

[tex]a^{4}[/tex]b is made up of [tex]a^{4}[/tex] and b

so [tex]a^{4}[/tex]b is a*a*a*a*b

a*a*b is in both a²b³ and [tex]a^{4}[/tex]b, so the GCF out of a²b³ and [tex]a^{4}[/tex]b is a²b

Now multiply 9 and a²b together, as they are only the GCF of the parts of the monomials

9*a²b=9a²b

there's the greatest common factor of the 2 monomials

Hope this helps!

Answer:

d=35000Km

Step-by-step explanation:

After 20h I traveled for

s1=1250*20=25000Km

My friend

s2=500*20=10000Km

Therefore d=25000+10000=35000Km

Answer:

I don't really understand the question

Step-by-step explanation:

c

Answer:

7% probability that the next 2 cards are hearts.

Step-by-step explanation:

Cards are chosen without replacement, which means that the hypergeometric distribution is used to solve this question.

Hypergeometric distribution:

The probability of x successes is given by the following formula:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

In which:

x is the number of successes.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

In this question:

10 cards, which means that [tex]N = 10[/tex]

3 are hearts, which means that [tex]k = 3[/tex]

Probability that the next 2 cards are hearts:

This is P(X = 2) when n = 2. So

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

[tex]P(X = 2) = h(2,10,2,3) = \frac{C_{3,2}*C_{7,0}}{C_{10,2}} = 0.0667[/tex]

0.0667*100% = 6.67%

Rounded to the nearest whole number, 7% probability that the next 2 cards are hearts.

Answer:

Notice that for 3 out of the 4 numbers, there is a relationship between the x and the y coordinate of the number; for 3+i, -2i, -2-4i we have that the real part is larger by 2 from the imaginary part. Thus, the points are on the same line in the imaginary plane; they satisfy x=y+2 or Re{z}=Im{z}+2. However, 2-4i does not satisfy this equation since 2 is not equal to -4+2. Hence, this point does not belong to the line that the other 3 points define.

Step-by-step explanation:

Answer:

all real numbers

Algebra Examples

The domain of the expression is all real numbers except where the expression is undefined

Hello!

The domain of an exponential function is the crowd of all real numbers, so: x ∈ ℝ.

Good luck! :)

Answer:

9.2

Step-by-step explanation:

You can do this calculation with a calculator by taking the square root of 85.

Hi there!  

»»————-　★　————-««

I believe your answer is:  

9.2

»»————-　★　————-««  

Here’s why:

Assuming that you mean "the square root of 85 rounded to the nearest tenth..."  

⸻⸻⸻⸻

[tex]\boxed{\text{Calculating the Answer...}}\\\\\rightarrow \sqrt{85} = 9.21954445729....[/tex]

⸻⸻⸻⸻

Since the digit to the right of the tenth (the 1) is less than or equal to four, we round down.

⸻⸻⸻⸻

[tex]9.21954445729...\approx\boxed{9.2}[/tex]

⸻⸻⸻⸻  

»»————-　★　————-««  

Hope this helps you. I apologize if it’s incorrect.

Answer:

A

Step-by-step explanation:

Answer:

the answer is B. (0,0) (5,-3) (4,1)

please mark me brainlist

Step-by-step explanation:

Answer:

Your answer is

Step-by-step explanation:

Your answer is B.(0, 0), (5, -3), (4, 1)

Answer:

0.9802 = 98.02% probability that the proportion of defective bottles in a sample of 602 bottles would differ from the population proportion by less than 4%

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

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.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

A bottle maker believes that 23% of his bottles are defective.

This means that [tex]p = 0.23[/tex]

Sample of 602 bottles

This means that [tex]n = 602[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.23[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.23*0.77}{602}} = 0.0172[/tex]

What is the probability that the proportion of defective bottles in a sample of 602 bottles would differ from the population proportion by less than 4%?

p-value of Z when X = 0.23 + 0.04 = 0.27 subtracted by the p-value of Z when X = 0.23 - 0.04 = 0.19.

X = 0.27

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

By the Central Limit Theorem

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

[tex]Z = \frac{0.27 - 0.23}{0.0172}[/tex]

[tex]Z = 2.33[/tex]

[tex]Z = 2.33[/tex] has a p-value of 0.9901

X = 0.19

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

[tex]Z = \frac{0.19 - 0.23}{0.0172}[/tex]

[tex]Z = -2.33[/tex]

[tex]Z = -2.33[/tex] has a p-value of 0.0099

0.9901 - 0.0099 = 0.9802

0.9802 = 98.02% probability that the proportion of defective bottles in a sample of 602 bottles would differ from the population proportion by less than 4%

Answer:

Step-by-step explanation:

[tex]\frac{34-40}{8}= -.75[/tex]

Answer:

Im sorry but why is this a question? Like what school gives this out

Answer:

Step-by-step explanation:

I'm sure he was making a joke at the expense of people who rely on mathematics rather than common sense. It is funny, but then Twain was a remarkably funny author..

The problem is that the comparison is apt using some sort of proportion, but it is absurd to think that the land holding the river would also shrink a proportional amount.  

The river reached a minimum (presumably) in 1875 by cutting out all the loops that were there in 1700. The Mississippi was then a straight line from it's beginning to its delta on the gulf of Mexico. It could not get any shorter. Still, Twain managed to get laughs with his whimsical humor.

Thanks for posting. This made my evening.

Answer:

D. KI

Step-by-step explanation:

KI intersects a minimum of two points meaning it is the definition of a secant.

Step-by-step explanation:

You can conclude that 82% of all shoppers will do business with any retailer of any size aslong as they are on the internet.

82% of 2700 = 0.82 * 2700 =2214

which makes the other responder correct.

Answer:

[tex]n = 5\frac{10}{13}[/tex]

Step-by-step explanation:

Given

[tex]Call = 6\frac{1}{2}[/tex] cups

[tex]Recipe = 37\frac{1}{2}[/tex] ounce

Required

Number of ounces per cup (n)

To do this, we simply divide the Recipe by the call

So, we have:

[tex]n = \frac{Recipe}{Call}[/tex]

[tex]n = 37\frac{1}{2} \div 6\frac{1}{2}[/tex]

Express as improper fraction

[tex]n = \frac{75}{2} \div \frac{13}{2}[/tex]

Rewrite as:

[tex]n = \frac{75}{2} * \frac{2}{13}[/tex]

[tex]n = \frac{75}{13}[/tex]

[tex]n = 5\frac{10}{13}[/tex]

The equation "a - 3x = 0" is correctly written because it follows the standard format of an algebraic equation.

Given that,

All the equations are,

1. a + 0.2x

2. 5b - 5x + 2

3. a - 3x = 0

Now, from equation ''a - 3x = 0'',

In this equation, the variable "a" subtracted from 3 times the variable "x" equals zero.

The equal sign (=) indicates that the expression on both sides of the equation is equivalent.

The equation is properly balanced and expresses equality between the two sides.

It accurately represents a relationship between the variables "a" and "x" where the value of "a" is dependent on the value of "x" in order to satisfy the equation.

So, The correctly written algebraic equation is:

a - 3x = 0

To learn more about the equation visit:

brainly.com/question/28871326

#SPJ4

Answer:

D = [4, 10]

Step-by-step explanation:

Since the line starts when x = 4, the domain begins there. And since the line ends when x=10, the domain ends there.

Answer:

I think A

Step-by-step explanation:

Answer:

annualy=$3689.62

semiannually=$3695.27

monthly=$3700.06

weekly=$3700.81

daily=$3701.00

Continuously=$3701.03

Step-by-step explanation:

Given:

P=3000

r=3%

t=7 years

Formula used:

Where,

A represents Accumulated amount

P represents (or) invested amount

r represents interest rate

t represents time in years

n represents accumulated or compounded number of times per year

Solution:

(i)annually

n=1 time per year

[tex]A=3000[1+\frac{0.03}{1} ]^1^(^7^)\\ =3000(1.03)^7\\ =3689.621596\\[/tex]

On approximating the values,

A=$3689.62

(ii)semiannually

n=2 times per year

[tex]A=3000[1+\frac{0.03}{2}^{2(4)} ]\\ =3000[1+0.815]^14\\ =3695.267192[/tex]

On approximating the values,

A=$3695.27

(iii)monthly

n=12 times per year

[tex]A=3000[1+\frac{0.03}{12}^{12(7)} \\ =3000[1+0.0025]^84\\ =3700.0644[/tex]

On approximating,

A=$3700.06

(iv) weekly

n=52 times per year

[tex]A=3000[1+\frac{0.03}{52}]^3^6 \\ =3000(1.23360336)\\ =3700.81003[/tex]

On approximating,

A=$3700.81

(v) daily

n=365 time per year

[tex]A=3000[1+\frac{0.03}{365}]^{365(7)} \\ =3000[1.000082192]^{2555}\\ =3701.002234[/tex]

On approximating the values,

A=$3701.00

(vi) Continuously

[tex]A=Pe^r^t\\ =3000e^{\frac{0.03}{1}(7) }\\ =3000e^{0.21} \\ =3000(1.23367806)\\ =3701.03418\\[/tex]

On approximating the value,

A=$3701.03

Answer:

pixxer

Step-by-step explanation:

please pick inside please

Answer:

I dont now

Step-by-step explanation:

plz conprendation