There are 60 students in a classroom, 50% of the students are
boys. 30% of the boys and 60% of the girls want to buy the
new textbook. How many students want to buy the new
textbooks?
___ students
Answer:
28
Step-by-step explanation:
If 50% of students are boys that means there are 30 boys and 30 girls. Then if 30% of boys are 10 and 60% of girls are 18. You add 18+10 and that gives you 28.
Carlos is blowing air into a spherical soap bubble at the rate of 5 cm3/sec.
How fast is the radius of the bubble changing when the radius is 10 cm? (Round your answer to four decimal places.)
How fast is the surface area of the bubble changing at that time? (Round your answer to one decimal places.)
Answer:
The answer is below
Step-by-step explanation:
a) dV/dt = 5 cm³/s
The volume (V) of the bubble is:
[tex]V=\frac{4}{3} \pi r^3\\\\Differentiating\ with\ respect\ to \ time(t)\\\\\frac{d}{dt}(V)=4\pi r^2 \frac{dr}{dt} \\\\Substituting\ \frac{d}{dt}(V)=5\ cm^3/s \ and\ r = 10\ cm\\\\5 = 4\pi *10^2*\frac{dr}{dt}\\\\5=400\pi *\frac{dr}{dt}\\\\\frac{dr}{dt}=0.004\ cm/s[/tex]
b) The surface area of the sphere (A) is:
[tex]A=4\pi r^2\\\\Differentiating\ w.r.t.\ t:\\\\\frac{dA}{dt}= 8\pi r\frac{dr}{dt} \\\\r=10, dr/dt=0.004\\\\\frac{dA}{dt}= 8\pi *10*0.004\\\\\frac{dA}{dt}=1\ cm^2/s[/tex]
The rate at which the radius of the bubble is changing at that time is [tex]0.0125 \pi cm^2/s[/tex]
The rate at which the surface area of the bubble is changing at that time is [tex]\pi^2 cm^2/s[/tex]
The formula for calculating the volume of a sphere is expressed as;
[tex]V =\frac{4}{3} \pi r^3[/tex]
r is the radius of the sphere
Differentiating the volume with respect to time;
[tex]\frac{dV}{dt} = \frac{dV}{dr} \times \frac{dr}{dt} \\\frac{dV}{dt} = 4 \pi r^2\frac{dr}{dt}[/tex]
Given the following parameters
dV/dt = 5 cm^3/sec.
r = 10 cm
Substitute into the formula to get dr/dt
[tex]\frac{dV}{dt} = 4 \pi (10)^2 \times \frac{dr}{dt}\\5 = 400 \pi \times \frac{dr}{dt}\\ \frac{dr}{dt}=0.0125 \pi cm/s\\[/tex]
The surface area of the bubble is expressed as:
[tex]S = 4 \pi r^2\\\frac{dS}{dt} = \frac{dS}{dr}\times \frac{dr}{dt}\\ \frac{dS}{dt} =8 \pi r \times 0.0125 \pi\\ \frac{dS}{dt} =\pi ^2 cm^2/s[/tex]
Hence the rate at which the surface area of the bubble is changing at that time is [tex]\pi^2 cm^2/s[/tex]
Learn more here: https://brainly.com/question/12663882
Find the Surface Area:
Of the picture below
6cm
3 cm
3 cm
2 cm
Answer:
72 cm^2 OR 72 sq cm.
Step-by-step explanation:
6 x 5 = 30
10 x 3 = 30
2 x 6 = 12
30 + 30 + 12 = 72
Sorry, i don't exactly know how to explain it without drawing it. But i assure you it is correct.
Solve for X.
8=5
X 9
Answer: x = 14.4
Step-by-step explanation:
Answer:
x = 14.4Step-by-step explanation:
8/x = 5/9 just cross multiply
5x = 8(9)
x = 72/5 divide 5 both sides
x = 14.4
After 10 years, the principal on this mortgage is $136,683. How much of the next payment will go towards interest
Answer: 13,668 i think.
What is the domain of the relation?
✔ -4<=x<=6
What is the range of the relation?
✔ -4<=y<=4
Is the relation a function?
✔ yes
here are all the answers
Answer:
thx for ur help
Use the distributive property to remove the parentheses.
9(6-v)
Answer:
[tex]54-9v[/tex]
Step-by-step explanation:
To remove the parentheses by using the distributive law, we need to multiply [tex]9[/tex] to each term within the parentheses.
[tex]9(6-v) = 9(6) +9(-v)[/tex]
[tex]=54-9v[/tex]
Hope this helps :)
For every left-handed person, there are about 4-right handed people. If there are 30 students in a class, predict the number of students who are right-handed.
Answer:
There are 24 right handed students
Step-by-step explanation:
This is a ratio question so it would be represented as 1:4.
First you would do 1 + 4 which is 5.
Then do 30 ÷ 5 which is 6.
Finally multiply 6 by 4 and 1.
So 6 × 4 × 1 is 24.
So there are 24 students who are right handed.
Hope this makes sense!
Mr. Abdullah’s new car can travel 420 miles on a 12-gallon tank of gas. Determine how many miles he can travel on 8 gallons
Answer:
280
Step-by-step explanation:
It is known that 10% of the UNIVERSITY students own their own car. If a random sample of 10 students is taken, what is the probability that at most 2 have their own vehicle?
Probability of students having their own vehicle
= 2/10
= 1/5
Michelle works in the mall and her hours increase during busy shopping times of the year. Michelle has a plan to
save $45 each week for 7 weeks, and then increase that amount by $30 for the next 8 weeks during the busy time,
then go back to $45 per week. If Michelle's plan is to save $1185, how many weeks total will she need to save?
Show your work
12
II
Answer:
The total number of weeks Michelle needs to save is 29.
Step-by-step explanation:
Michelle plans to save $1185 in a number of weeks to determine later.
In the first 7 weeks, she will save $45 each week for a total of
$45 * 7 = $315
In the next 8 weeks, she will save $30 each week for a total of:
$30 * 8 = $240
During these 15 weeks, she has saved
$315 + $240 = $555
She still has a remaining $1185 - $555 = $630 to save.
Those $630 will be saved in a number of weeks at $45 per week, thus the number of weeks is:
$630 / $45 = 14 weeks
Total weeks = 15 + 14 = 29
The total number of weeks Michelle needs to save is 29.
Simplify (3√-5 +2)(4√-12 -1)
Thank you in advance
Full steps so I can understand!
Answer:
12√60 - 3√-5 + 8√-24 -2
Step-by-step explanation:
Use the distributive property
Multiply each by the other term outside their parantheses
for example multiply 3√-5 by 4√-12 and 3√-5 by -1.
Answer:
√
28
√
4
=
2
7
⋅
2
√
7
14
√
7
14
√
7
Explanation:
28
is the same as
2
×
14
witch in turn is the same as
2
2
×
7
Write as
7
√
2
2
×
7
Taking the
2
2
'outside' the square root changes it from
2
2
to
2
7
√
2
2
×
7
=
7
×
2
×
√
7
14
√
7
Step-by-step explanation:
The length of a rectangle is (2x+3) and the width is x-5. If the perimeter is 44cm what is the length of the rectangle?
Perimeter = 2x length + 2x width.
2(2x+3) + 2(x-5) = 44
Simplify:
4x + 6 +2x -10 = 44
Combine like terms:
6x -4 = 44
Add 4 to both sides:
6x = 48
Divide both sides by 6:
X = 8
Now replace x with 8 in the equation for length:
2x + 3 = 2(8) +3 = 16 + 3 = 19 cm
Length = 19 cm
What value of θ makes the statement true?
cos(θ)=sin(θ/3−10)
The required value of θ for the trigonometric function cos(θ)=sin(θ/3-10) is 60°.
What are trigonometric functions?The basic Trigonometric functions are sine, cosine, tangent, secant, cosecant and cotangent.
The given equation is,
cos(θ)=sin(θ/3-10) (1)
To find the value of θ,
Change the whole equation into one trigonometric function,
Since, cos(θ)=sin(90-θ)
Substitute this value in equation (1)
sin(90-θ)=sin(θ/3-10)
⇒90-θ=θ/3-10
⇒4θ/3=80
⇒θ=60
The value of θ is 60°.
To know more about Trigonometric Function on:
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Graph the line with the equation y = -x - 1.
that is what the line will look like.
This is a straight line. We only need 2 points to graph a straight line.
Let x = 0
y = -(0) - 1
y = -1
Our first point is (0,-1).
Let x = 1
y = -(1) - 1
y = -2
Our second point is (1,-2).
See attachment for graph.
find the area of a circle that has a radius of 7/10 cm. use 22/7 for pi
Answer:
77/50 ≈ 1.54
Step-by-step explanation:
A=πr²
A = (22/7)(7/10)²
A = 77/50
A ≈ 1.54
PLEASE MARK IT AS BRAINLIEST
Can you help with the 2 that are not correct?
Answer:
MPO=MNO
NPO=MNP
Step-by-step explanation:
MPO=MNO because MPO opposite angles of a parallelogram are congruent.
MNO is the top right angle of the parallelogram and so the opposite side of that is MPO or OPN whatever way you want to write it.
NPO=MNP because they are alternate interior angles. (If you don't understand what that means I can come back and explain it)
Find the area of the shape shown below
Answer:
18 MARK AS BRAINLIEST OR ELSE!!!!
Step-by-step explanation:
area = 1/2h(sum of bases)
area = 1/2x3(3+9)
area = 1/2 of 36
area = 18
Teresa plans to attend college in 3 years. She will need $13,600 for the first-year cost. Her uncle gave her a special gift of $10,000 to use toward the cost. How much must Teresa save each month to have enough for the first-year cost?
Answer:
100$ per month
Step-by-step explanation:
If the ages in a classroom were 11, 12, 12, 13, 13, 14 - what would the median age be if you added someone that was 10 years old?
Answer: 12 years old
Step-by-step explanation:
10,11,12,12,13,13,14
The middle in these numbers is 12
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The ages of the winners of a cycling tournament are approximately bell shaped. The mean age is 27.9 years, with a standard deviation of 3.3 years. The winner in one reason year was 26 years old
Answer:
200
Step-by-step explanation:
anybody understand this ? please help me .
Answer:its a or b
Step-by-step explanatio
Answer:
The answer is (2)
Step-by-step explanation:
We know that to the distance between two numbers on a number line, we subtract the smaller number from the larger number. For instance, the difference between [tex]5[/tex] and [tex]3[/tex] is simply [tex]5-3[/tex], which is [tex]2[/tex]. With that being said, variables such as [tex]p[/tex] or [tex]q[/tex] differ from a question to another. Sometimes, the [tex]p[/tex] is larger, but sometimes the [tex]q[/tex] is. If we don’t know which one is which, we can subtract them in any order and take the absolute value of that result. If the result of subtraction is positive, great! The absolute value of that is still positive ([tex]5-3=2\\|5-3|=2[/tex]) If it’s not, now it is! (e.g., [tex]|3-5|=2[/tex]! Therefore, the answer is (2) [tex]|p-q|[/tex].
Sales of video games and consoles fell from $1.15 million to $1.03 million in 1 year. Find the percent decrease.
Answer:100 times 7
Step-by-step explanation: because
Three letters are randomly chosen from PROBABILITY. What is the probability that at least one of the letters is B?
Answer:
2/11
Step-by-step explanation:
thats the probability
Answer:
2/11
Step-by-step explanation:
if i have 1000 dollars and lose 1000 dollars how much do i have left 100 points
The mathematical answer would happen to be... 0
Answer:
0
Step-by-step explanation:
Use Newton's method to approximate the given number correct to eight decimal places. 4√73
Answer:34.17601498.
Step-by-step explanation:
Newton's method of approximation is used to approximate values.
The value of [tex]\mathbf{4\sqrt{73}}[/tex] is 34.17601498
Let the number be x.
So, we have:
[tex]\mathbf{x = 4\sqrt{73}}[/tex]
Square both sides
[tex]\mathbf{x^2 = 1168}[/tex]
Subtract 1168 from both sides
[tex]\mathbf{x^2 - 1168 = 0}[/tex]
Express as a function
[tex]\mathbf{f(x) = x^2 - 1168 }[/tex]
Set x1 to 73/2.
So, we have:
[tex]\mathbf{x_1 = \frac{73}{2} = 36.5}[/tex]
Where:
[tex]\mathbf{x_{n+1} = x_n- \frac{x_n^2-1168}{2x_n}}[/tex]
So, we have:
[tex]\mathbf{x_{1+1} = x_1- \frac{x_1^2-1168}{2x_1}}[/tex]
[tex]\mathbf{x_{2} = x_1- \frac{x_1^2-1168}{2x_1}}[/tex]
This gives
[tex]\mathbf{x_{2} = 36.5- \frac{36.5^2-1168}{2 \times 36.5}}[/tex]
[tex]\mathbf{x_{2} = 34.25}[/tex]
[tex]\mathbf{x_{3} = x_2- \frac{x_2^2-1168}{2x_2}}[/tex]
[tex]\mathbf{x_{3} = 34.25- \frac{34.25^2-1168}{2 \times 34.25}}[/tex]
[tex]\mathbf{x_{3} = 34.1760948905}[/tex]
[tex]\mathbf{x_{4} = x_3- \frac{x_3^2-1168}{2x_3}}[/tex]
[tex]\mathbf{x_{4} = 34.1760948905- \frac{34.1760948905^2-1168}{2\times 34.1760948905}}[/tex]
[tex]\mathbf{x_{4} = 34.1760149814}[/tex]
[tex]\mathbf{x_{5} = x_4- \frac{x_4^2-1168}{2x_4}}[/tex]
[tex]\mathbf{x_{5} = 34.1760149814- \frac{34.1760149814^2-1168}{2\times 34.1760149814}}[/tex]
[tex]\mathbf{x_{5} = 34.1760149813}[/tex]
The values of x4 and x5 are the same up till the 8th decimal place.
Hence, the value of [tex]\mathbf{4\sqrt{73}}[/tex] is 34.17601498
Read more about Newton's method of approximation at:
https://brainly.com/question/14279052
10. Anna divided integer A by -3 and got 8. Then she divided 8 by integer B and got -4. Find the quotient of integer A and B. I talling 2020
Answer:
cant help uu :(
Step-by-step explanation:
what is 32 divided by 97
Answer:
0.32989690721
Step-by-step explanation:
Answer:
rounded to the nearest hundred: 0.33
Step-by-step explanation:
hope this helps :3
find if the series converges conditionally, converges absolutely, or diverges ∑k=1 ∞ (k^2k 3^k)/k!
Answer:
Diverges
Step-by-step explanation:
Using the ratio test to test the series: