Answer:
The number A(t) of pounds of salt in the tank at time t = [tex]\frac{3t(100 - t)}{25}[/tex]
Step-by-step explanation:
Given - A large tank is filled to capacity with 400 gallons of pure water. Brine containing 3 pounds of salt per gallon is pumped into the tank at a rate of 4 gal/min. The well-mixed solution is pumped out at a rate of 8 gals/min.
To find - Find the number A(t) of pounds of salt in the tank at time t.
Proof -
Given that,
Capacity of water = 400 gallons
rate in flow = 4 gal/min
rate out flow = 8 gal/min
Concentration in = 3 lbs/gal
Concentration out = (Amount of salt at time t )/ (Solution in tank at time t)
Now,
Let
A(t) = Amount of salt in the tank at time t
Now,
Initially tank has 400 gallons of water, So
A(0) = 0 ................(1)
Now,
Rate of change in the amount of salt = [tex]\frac{d}{dt} A(t)[/tex]
= (Rate in flow )( Concentration In) - (Rate out flow )( Concentration out)
= (4) (3) - (8) ([tex]\frac{A(t)}{400 - 4t)}[/tex]
= 12 - [tex]\frac{2A(t)}{100 - t)}[/tex]
⇒[tex]\frac{d}{dt} A(t)[/tex] + [tex]\frac{2A(t)}{100 - t)}[/tex] = 12
Now,
Integrating Factor, I.F = [tex]e^{\int {\frac{2}{100 - t} } \, dt }[/tex]
= [tex]e^{-2ln(100 - t)}[/tex]
= (100 - t)⁻²
⇒I.F = (100 - t)⁻²
The solution becomes
A (I.F) = ∫ (I.F)(12) dt + C
⇒A (100 - t)⁻² = ∫12(100 - t)⁻² dt + C
⇒A (100 - t)⁻² = -12(100 - t)⁻¹ (-1) + C
⇒A(t) = [tex]12(100 - t)+ C(100 - t)^{2}[/tex]
Now,
We have A(0) = 0
⇒C = -12/100
∴ we get
A(t) = 12(100 - t) - [tex]\frac{12}{100}[/tex] (100 - t)²
= 12(100 - t) [ 1 - [tex]\frac{100 - t}{100}[/tex] ]
= 12(100 - t) ([tex]\frac{t}{100}[/tex])
= [tex]\frac{3t(100 - t)}{25}[/tex]
⇒A(t) = [tex]\frac{3t(100 - t)}{25}[/tex]
∴ we get
The number A(t) of pounds of salt in the tank at time t = [tex]\frac{3t(100 - t)}{25}[/tex]
v=Xf; speed = wavelength x frequency
f= 1/T; frequency = 1/Period
Problems: 1. The frequency of a wave is 4.0 x 10 Hz. What is its wavelength?
2. A wave with a frequency of 31,200 Hz and travels at 790m/s? What is the wavelength in centimeters?
3. A wave has a wavelength of 25cm and a velocity of 630 m/s, what is the frequency?
In ΔMNO, the measure of ∠O=90°, the measure of ∠M=46°, and NO = 96 feet. Find the length of OM to the nearest tenth of a foot.
Answer:
92.7 ft
Step-by-step explanation:
Pls helppppppp!!!!!!!!!!!
Answer:
part of it is cutted out show a better picture please ill answer it
Step-by-step explanation:
Graph the compound inequality on the number line. x> -7 and x<-3
Answer:
Step-by-step explanation:
all muntiple of 5 is an odd number true proposition?
The correct answer is false.
Multiples 5 include: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, etc.
Bold numbers: even
Normal numbers: odd
A restaurant chef has designed a new set of dishes for his menu. His set of dishes contains 10 10 main courses, and he will select a subset of them to place on the menu each night. To ensure variety of main courses for his patrons, he wants to guarantee that a night's menu is neither completely contained in nor completely contains another night's menu. What is the largest number of menus he can plan using his 10 10 main courses subject to this requirement
Answer:
252 menu
Step-by-step explanation:
Total number courses, n = 10
The largest number of menu the chef can plan using his 10 main courses.
There are various combinations of menu obtainable from the available courses :
Ranging from :
nC0 to nCn
The largest number of menu he can plan is the highest output obtainable between :
10C0 to 10C10
10C0 = 1
10C1 = 10
10C2 = 45
10C3 = 120
10C4 = 210
10C5 = 252
10C6 = 210
10C7 = 120
10C8 = 45
10C9 = 10
10C10 = 1
Hence, the largest number of menu he can plan using his 10 main courses is 252
suppose 11 out of 22 students said they were attending the football game. how many students out of 580 would you expect to attend the football game.
Answer: 290
Step-by-step explanation:
11/22 is half so the percentage would be 50%.
As we know it's a half you would just have to half or divide 580 by 2.
580÷2=290
Hope this helps :)
Simplify the expression and find its value please help i will give brainliest
Answer:
7.5
Step-by-step explanation:
a - (2a-1)/a
--------------------
(1-a)/3a
Multiply the top and bottom by 3a
a - (2a-1)/a 3a
-------------------- * ---------------
(1-a)/3a 3a
3a *a - (2a-1)*3a/a
------------------------
(1-a)/3a *3a
Simplify
3a *a - (2a-1)*3
------------------------
(1-a)
3a^2 - 6a+3
------------------------
(1-a)
Factor
3( a^2 -2a+1)
-----------------------
-(a-1)
3(a-1)^2
---------------
-(a-1)
Cancel like terms
-3(a-1)
Letting a = -1.5
-3( -1.5-1)
-3 (-2.5)
7.5
Solve three fourths times two thirds. Leave answer as improper fraction
a. 5/12
b.6/12
c.5/7
d. 6/7
Answer:
B) [tex]\frac{6}{12}[/tex]
Step-by-step explanation:
Note that you do not need to simplify. Simply multiply straight across:
[tex]\frac{3}{4} * \frac{2}{3} = \frac{3 * 2}{4 * 3} = \frac{6}{12}[/tex]
B) [tex]\frac{6}{12}[/tex] is your answer.
`
Help w number 6 pls!
Answer:
Y is 66 and x is 48Step-by-step explanation:
So, if u put together x and y, it'll make 48 because
the arranged two numbers will go to 9.
So, that's it! :)Mark works as a librarian and makes $16.75 per hour. He gets paid time-and-a-half for overtime. How much will he make if he works 52 hours this week?
Play media comment.
Group of answer choices
$670.00
$971.50
$1,005.00
$871.00
PLZZZ HURRY
Answer:
$871.00
Step-by-step explanation:
whats 56787577765445789990 times 3695669870
Answer:
2.0986814e+29
Step-by-step explanation:
Answer:
what
Step-by-step explanation:
punch your calculator to find out
even the calculator might not give u the exact value
2. Karen sells newspaper subscriptions. She earns $12 for each daily subscription and $4 for each Sunday- only subscription. How much will she earn if she sells 24 daily and 13 Sunday-only subscriptions in a week?
Your Answer;
❀♡ 12 x 24 + 4 x 13 = 340 ♡❀
Answer:
340
Step-by-step explanation:
Of the pets in the pet show, 10/12 are cats. 6/10 of the cats are calico cats. What fraction of the cats are calico cats?
Answer:
6/10, simplified 3/5
Step-by-step explanation:
kinda tricky, but the fraction is stated right out.
Answer:
3/5
Step-by-step explanation:
what is the slope of the line for 3x+ 4y = 20?
Answer:
[tex]-\frac{3}{4}[/tex]
Step-by-step explanation:
Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
PEMDAS is the order of operation, and stands for:
Parenthesis
Exponents (& Roots)
Multiplication
Division
Addition
Subtraction
~
First, subtract 3x from both sides of the equation:
3x (-3x) + 4y = (-3x) + 20
4y = -3x + 20
Next, divide 4 from both sides of the equation:
(4y)/4 = (-3x + 20)/4
y = (-3/4)x + 5
[tex]y = -\frac{3}{4}x + 5[/tex]
~
Note the equation.
y = mx + b
y = y
m = slope = [tex]-\frac{3}{4}[/tex]
x = x
b = y-intercept = 5
if 4=p (p+5)=21 find p
Answer:
p=16?
16+5=21?
Step-by-step explanation:
16+5=21
i will give a crown if you are the first one to answer and if you get it right and if you just get it right then i will i give you a full star rating and a thanks
Answer:
30x+15
Step-by-step explanation:
shamika grew by 14 cm in the past year, and is now 1.33 meters tall. how tall in meters was shamika last year
Solve this inequality for x.
A.
B.
C.
D.
Answer:
D
Step-by-step explanation:
dd
g Based on historical data, your manager believes that 32% of the company's orders come from first-time customers. A random sample of 146 orders will be used to estimate the proportion of first-time-customers. What is the probability that the sample proportion is greater than than 0.43
Answer:
0.0022 = 0.22% probability that the sample proportion is greater than than 0.43
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 zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes 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]
Based on historical data, your manager believes that 32% of the company's orders come from first-time customers.
This means that [tex]p = 0.32[/tex]
Mean and standard deviation:
Sample of 146 means that [tex]n = 146[/tex]
[tex]\mu = p = 0.32[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.32*0.68}{146}} = 0.0386[/tex]
What is the probability that the sample proportion is greater than than 0.43?
This is 1 subtracted by the pvalue of Z when X = 0.43. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.43 - 0.32}{0.0386}[/tex]
[tex]Z = 2.85[/tex]
[tex]Z = 2.85[/tex] has a pvalue of 0.9978
1 - 0.9978 = 0.0022
0.0022 = 0.22% probability that the sample proportion is greater than than 0.43
six people wen put to dinner, split the check, and paid $18. How much was the check
Answer:
$180
Step-by-step explanation:
$18 × 6
=$180
That's your answer
I need help with solving this
Answer:
x=12
.......................
What is the probability of flipping a coin 85 times and getting tails 30 times or
fewer?
A. 99.8%
B. 33.2%
C. 95.9%
D. 0.4%
Answer:
C
Step-by-step explanation:
Answer:
0.4
Step-by-step explanation:
Help me solve this, it’s trig
Answer:
The answer is 6.451 or 6.5 rounded
Step-by-step explanation:
The way to solve this is to find all the degrees inside the triangle first
you have two given degrees which are 21 and 90 degrees
add those numbers up and subtract it from 180. That is the last corner degree
you then use that information to find all the side lengths using the given hypotenuse length.
Btw its geometry not really trig.
Answer: 6.45 units
Step-by-step explanation:
To solve for x, we will set up an equation using the trigonometric functions. We are given an angle (21 degrees), the opposite side of that angle (x), and the hypotenuse (18). For this, we will use the sine function.
sin(21) = [tex]\frac{opposite}{hypotenuse }[/tex]
sin(21) = [tex]\frac{x}{18}[/tex]
18sin(21) = x
x = 18sin(21)
x = 6.4506230 ≈ 6.45 units
Can someone please help with this one I will report false/fake answers please someone.
I will also give brainiest.
Answer:
I belive it is 2.9716
Step-by-step explanation:
Happy Tuesday! Looking for some help with my geometry.
Please only answer if you know the answer, the comment section is right below. Please don't waste my points!
Also, please show all of your work, you are trying to help me better understand the concept, not just give me the answer.
The image is down below. This is a multi step question and please answer all five. Show work! Thanks!
Answer:
Q1
cos 59° = x/16x = 16 cos 59°x = 8.24Q2
BC is given 23 mi
Maybe AB is needed
AB = √34² + 23² = 41 (rounded)Q3
BC² = AB² - AC²BC = √(37² - 12²) = 35Q4
Let the angle is x
cos x = 19/20x = arccos (19/20)x = 18.2° (rounded)Q5
See attached
Added point D and segments AD and DC to help with calculation
BC² = BD² + DC² = (AB + AD)² + DC²Find the length of added red segments
AD = AC cos 65° = 14 cos 65° = 5.9DC = AC sin 65° = 14 sin 65° = 12.7Now we can find the value of BC
BC² = (19 + 5.9)² + 12.7²BC = √781.3BC = 28.0 ydAll calculations are rounded
5x -30 = 3x + 60
How many solutions are there
Answer:
one solution
Step-by-step explanation:
5x - 30 = 3x + 60
2x - 30 = 60
2x = 90
x = 45
What are the two solutions to 2x2−x−4=0 ? Use the quadratic equation
The number of bacterial colonies of a certain type in samples of polluted water has a Poisson distribution with a mean of 3 per cubic centimeter (cm3). (a) If eight 1 cm3 samples are independently selected from this water, find the probability that at least one sample will contain one or more bacterial colonies. (Round your answer to four decimal places.) 1 Correct: Your answer is correct. seenKey 1.000 (b) How many 1 cm3 samples should be selected in order to have a probability of approximately 0.95 of seeing at least one bacterial colony
Answer:
a) 1 = 100% probability that at least one sample will contain one or more bacterial colonies.
b) 1 sample should be selected in order to have a probability of approximately 0.95 of seeing at least one bacterial colony
Step-by-step explanation:
To solve this question, we need to understand the poisson and the binomial distributions.
Poisson distribution:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
In which
x is the number of sucesses
e = 2.71828 is the Euler number
[tex]\mu[/tex] is the mean in the given interval.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [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]
And p is the probability of X happening.
Probability of a single sample having at least one bacterial colonies.
Poisson distribution with a mean of 3 per cubic centimeter (cm3), which means that [tex]\mu = 3[/tex]
This is:
[tex]P(X \geq 3) = 1 - P(X = 0)[/tex]
In which
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
[tex]P(X = 0) = \frac{e^{-3}*3^{0}}{(0)!} = 0.0495[/tex]
[tex]P(X \geq 3) = 1 - P(X = 0) = 1 - 0.0495 = 0.9505[/tex]
(a) If eight 1 cm3 samples are independently selected from this water, find the probability that at least one sample will contain one or more bacterial colonies.
Multiples samples means that the binomial distribution is used.
0.9505 probability of a sample having at least one colony, which means that [tex]p = 0.9505[/tex]
8 samples means that [tex]n = 8[/tex]
The desired probability is:
[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]
In which
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{8,0}.(0.9505)^{0}.(0.0495)^{8} \approx 0[/tex]
[tex]P(X \geq 1) = 1 - P(X = 0) = 1 - 0 = 1[/tex]
1 = 100% probability that at least one sample will contain one or more bacterial colonies.
(b) How many 1 cm3 samples should be selected in order to have a probability of approximately 0.95 of seeing at least one bacterial colony
We have to find [tex]P(X \geq 1)[/tex] for samples of 1,2,3,..., until this probability is 0.95. So
n = 1
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{1,0}.(0.9505)^{0}.(0.0495)^{1} = 0.0495[/tex]
[tex]P(X \geq 1) = 1 - P(X = 0) = 1 - 0.0495 = 0.9505[/tex]
0.9505 > 0.95
1 sample should be selected in order to have a probability of approximately 0.95 of seeing at least one bacterial colony
In a toy box there are 3 toy cars, 2 dolls, and 5 balls. What is he probability of choosing a toy car