Answer:
The time it'd take for the element to have 15 g of mass is approximately 68 min.
Step-by-step explanation:
The radioactive decay of a substance is given by the following formula:
[tex]mass(t) = mass(0)*e^{-\lambda*t}[/tex]
Since the element has a half life of 12 minutes, this means that after this time the mass of the element will be half of it was originally, therefore:
[tex]\frac{mass(0)}{2} = mass(0)*e^{-\lambda*12}[/tex]
[tex]\frac{1}{2} = e^{-\lambda*12}[/tex]
[tex]ln(\frac{1}{2}) = -12*\lambda\\\lambda = -\frac{ln(0.5)}{12} =0.0577623[/tex]
Therefore the mass of the element is given by:
[tex]mass(t) = mass(0)*e^{-0.0577623*t}[/tex]
If the initial mass is 760 g and the final mass is 15 g, we have:
[tex]mass(t) = mass(0)*e^{-0.0577623*t}\\\\15 = 760*e^{-0.0577623*t}\\\\e^{-0.0577623*t} = \frac{15}{760}\\\\ln(e^{-0.0577623*t}) = ln(\frac{15}{760})\\\\-0.0577623*t = ln(\frac{15}{760})\\\\t = \frac{ln(\frac{15}{760})}{-0.0577623}\\\\t = 67.9555[/tex]
The time it'd take for the element to have 15 g of mass is approximately 68 min.
For a t distribution with 16 degrees of freedom, find the area, or probability, in each region.
a. To the right of 2.583
Answer:
[tex] P(t_{16}>2.583)[/tex]
And for this case we can use the complement rule and we got:
[tex]P(t_{16}>2.583)= 1- P(t_{16} <2.583)[/tex]
And if we use the t- table with df =16, we got:
[tex]P(t_{16}>2.583)= 1-0.990= 0.01[/tex]
Step-by-step explanation:
For this case we know that the degrees of freedom are given:
[tex] df = n-1= 16[/tex]
And we want to find the following probability:
[tex] P(t_{16}>2.583)[/tex]
And for this case we can use the complement rule and we got:
[tex]P(t_{16}>2.583)= 1-P(t_{16} <2.583)[/tex]
And if we use the t-table with df =16, we got:
[tex]P(t_{16}>2.583)= 1-0.990= 0.01[/tex]
What is the measure of L?
A. 25°
B. Cannot be determined
C. 39
D. 32°
Answer:
A. 25°
Step-by-step explanation:
25° is really the only logical answer.
What is the area of a rectangles with the side lengths 7/6 inches and 6/7 inches?
Answer:
1 in^2
Step-by-step explanation:
area of a rectangle=l*w
l=7/6
w=6/7
7/6 * 6/7 = 1
Solve the equation. y + 6 = –3y + 26
Answer:
y = 5
Step-by-step explanation:
y + 6 = –3y + 26
Add 3y to each side
y+3y + 6 = –3y+3y + 26
4y +6 = 26
Subtract 6 from each side
4y+6-6 = 26-6
4y = 20
Divide by 4
4y/4 = 20/4
y = 5
The solution of y in the equation y + 6 = - 3y + 26 is,
⇒ y = 5
We have to given that;
Expression is,
⇒ y + 6 = - 3y + 26
Now, We can simplify as;
y + 6 = - 3y + 26
Add 3y to each side
y + 3y + 6 = - 3y + 3y + 26
4y + 6 = 26
Subtract 6 from each side
4y + 6 - 6 = 26 - 6
4y = 20
Divide by 4
4y/4 = 20/4
y = 5
Thus, The solution of y in the equation y + 6 = - 3y + 26 is,
⇒ y = 5
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Macy’s was offering a Memorial Day sale. The price of a shirt is now $21.25. The original price was $25. What is the percent of change from the original to the sale price?
Answer:
The original price drops by 15%.
Step-by-step explanation:
What was the drop in price? To answer that, subtract $21.25 from $25, which results in $3.75.
Now compare $3.75 to the original price, $25, through division, as follows:
$3.75
-------------- * 100% = 15%
$25
The original price drops by 15%.
x3 - 2x2 + 1 = 0 is a quadratic equation.
True
False
Answer:
false
Step-by-step explanation:
Answer:
False
Step-by-step explanation:
Quadratic equations have the highest degree on x as 2 (a squared value). The given equation has x^3 (assuming x3 is x^3 and not 3x), meaning that the equation is a cubic equation.
24. John buys 20 bunches of bananas
For N5. He sells them all for N6.50.
What is his percentage profit?
(a) 3/12%
(b) 20%
(c) 30%
(d) 762/13%
(e) 77%
Answer:
30%
Step-by-step explanation:
Profit(Gain)% = [tex]\frac{Selling price - Cost price}{Cost price} * 100%[/tex]
Selling price = N6.50
Cost price = N5
∴ Profit% = [tex]\frac{N6.50 - N5 }{N5} * \frac{100}{1}[/tex]
= [tex]\frac{1.5}{5} * \frac{100}{1}[/tex]
= (1.5 * 20)%
= 30%
Hope this helps!!!
An angle measures 32° less than the measure of its supplementary angle. What is the
measure of each angle?
Answer:
Step-by-step explanation:
x+x-32=180
2x-32=180
2x=180+32
2x=212
x=106
x-32=>106-32=74
What is the correct formula for calculating a 3 x 3 determinant?
a)abc+def+ghi-adg-beh-cfi
b)adg+beh+cfh-abc-beh-cfi
c)aei+bfg+cdh-gec-hfa-idb
Answer:
C
Step-by-step explanation:
just did it on edge
I need to know the answer
Answer:
y=3.65
X=11.85
Step-by-step explanation:
sin(60)=y/12
sin(60)×12=y
y=3.65
sin(30)=X/12
sin(30)×12=X
X=11.85
63 as a product of prime factors
Answer:
3*3 *7
Step-by-step explanation:
63 = 9*7
7 is prime but 9 is not
Break 9 into its factors
= 3*3 *7
All of these are prime
Answer:3x3x7
Step-by-step explanation:
The length of a rectangle is 15 meters more than the width. The perimeter is 50 meters. The width is:
Answer:
5 meters
Step-by-step explanation:
The perimeter of a rectangle can be expressed as 2l+2w.
2l+2w=50
l=w+15
Substitute:
2(w+15)+2w=50
2w+30+2w=50
4w+30=50
4w=20
w=5
Hope this helps!
The volume of a sphere is 45001 m3. Find the length of the radius
of the great circle.
Answer:
[tex]\large \boxed{\text{22.07 m}}[/tex]
Step-by-step explanation:
The formula for the volume (V) of a sphere is:
V = ⁴/₃πr³
We can use this equation to calculate the radius (r).
[tex]\begin{array}{rcl}45001 & = & \dfrac{4}{3} \pi r^{3}\\\\33750 & = &\pi r^{3}\\10740 & = &r^{3}\\r & = & \textbf{22.07 m}\\\end{array}\\\text{The radius of the great circle is $\large \boxed{\textbf{22.07 m}}$}[/tex]
What is the value of x in the equation below? −3x + 14 = 4x − 7 *
Answer:
x=3
Step-by-step explanation:
-3x+14=4x-7
-3x going to right and -7 is going to left and change sign
14+7=4x+3x
21=7x
21/7=3 , x=3
Answer:
-The value of [tex]x[/tex]:
[tex]x = 3[/tex]
Step-by-step explanation:
-Solve for the value of [tex]x[/tex]:
[tex]-3x + 14 = 4x - 7[/tex]
-Subtract both sides by [tex]4x[/tex] and combine [tex]-3x[/tex] and [tex]-4x[/tex] together:
[tex]-3x + 14 - 4x = 4x - 4x - 7[/tex]
[tex]-7x + 14 = -7[/tex]
-Subtract both sides by [tex]14[/tex]:
[tex]-7x + 14 - 14 = -7 -14[/tex]
[tex]-7x = -21[/tex]
-Divide both sides by [tex]7[/tex]:
[tex]\frac{-7x}{-7} = \frac{-21}{-7}[/tex]
[tex]x = 3[/tex]
So, the final answer is [tex]x = 3[/tex].
I need help people please help me
Answer:
10/4 = [tex]\frac{10}{4}[/tex]
Step-by-step explanation:
Mia is taking a multiple choice test with a total of 50 points available. Each question is worth exactly 2 points. What would be Mia's test score (out of 50) if she got 3 questions wrong? What would be her score if she got xx questions wrong?
Answer:
25
Step-by-step explanation:
Mia is taking a multiple choice test with a total of 50 points available. Each question is worth exactly 2 points. What would be Mia's test score (out of 50) if she got 3 questions wrong? What would be her score if she got xx questions wrong?
Answer:
$38
$56
Step-by-step explanation:
At a middle school, 30% of the students walk to school, 1/5 (20%) ride their bikes, 12.5 are dropped off by car, and the remaining students ride the bus to school.
Is there are 800 students who attend this school, how many students use each form of transportation?
Answer:
please give more clarification
Answer:
Walk: 240
Ride 160
Car 100
Rest 300
Step-by-step explanation:
Walk:
30%
.30 * 800 = 240
Ride
20%
.20 * 800 =160
Car
12.5%
.125 * 800 =100
Rest
100-30-20-12.5 =37.5
.375 * 800 = 300
A rectangle is 8 feet long. Its width is represented by "seven plus x feet." Which expression represents the area, in square feet, of the rectangle?
Answer:
[tex] \boxed{\sf Area \ of \ the \ rectangle = (8x + 56) \ square \ feet} [/tex]
Given:
Length = 8 feet
Width = (7 + x) feet
To find;
Area of the rectangle
Step-by-step explanation:
[tex] \sf Area \: of \: the \: rectangle = Length \times Width \\ \\ \sf \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 8 \times (7 + x)\\ \\ \sf \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = (8 \times 7) + (8 \times x)\\ \\ \sf \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 56 + 8x\\ \\ \sf \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = (8x + 56) \: square \: feet[/tex]
The ratio of ages of kissi and esinam is 3:5 and esinam is 3:5 The sum of ages of all 3 is 147 years.whats the age difference between oldest and youngest ?
Answer:
48 years.
Step-by-step explanation:
Consider the complete question is "The ratio of ages of kissi and esinam is 3:5 and that of esinam and lariba is 3:5. The sum of ages of all 3 is 147 years. whats the age difference between oldest and youngest ?"
It is given that
Kissi : Esinam = 3:5 = 9:15
Esinam : Lariba = 3:5 = 15:25
So, the combined ratio is Kissi : Esinam : Lariba = 9:15:25
Let ages of Kissi, Esinam, Lariba are 9x, 15x and 25x.
Sum of ages of all 3 is 147 years.
[tex]9x+15x+25x=147[/tex]
[tex]49x=147[/tex]
[tex]x=3[/tex]
The value of x is 3. So, the age of all three are
[tex]Kissi=9x=9(3)=27[/tex]
[tex]Esinam=15x=15(3)=45[/tex]
[tex]Lariba=25x=25(3)=75[/tex]
Since Lariba is oldest and Kissi is youngest, therefore, the difference between their ages is
[tex]75-27=48[/tex]
Hence, difference between oldest and youngest is 48 years.
Anna bought a backpack for $36.
She also bought a lunch box for $15.
Which is the total amount of money Anna spent?
Answer:
Anna spent $51 in all.
Step-by-step explanation:
36+15=51
Answer:
$51
Step-by-step explanation:
Anna bought two items: a backpack and a lunch box. If we want to find the total amount of money Anna spent, we have to add the price of the backpack and the price of the lunchbox.
price of backpack+price of lunchbox
The backpack cost $36 and the lunchbox cost $15
$36+$15
Add 36 and 14
$51
Anna spent $51 in total
La figura MNPQ es un rombo. Si 2θ – Φ =60°. Calcula el valor de “x”. Dime los fundamentos y principios que utilizas.
Answer:
x = 30°
Step-by-step explanation:
Donde 2θ - Φ = 60 °, tenemos;
∠QMN = ∠QPM
Ф + ∠P / 2 + (180 - θ) = 180 (Suma de ángulos en un triángulo ΔQLP)
Por lo tanto, Ф + ∠P / 2 - θ = 0
Por lo tanto, ∠P / 2 = θ - Ф, también
270 ° + θ + x + ∠P / 2 = 360 (Suma de ángulos en un NOLP cuadrilátero) da
270 ° + θ + x + θ - Ф = 270 ° + 2 · θ - Ф + x = 360
Como 2 · θ - Ф = 60 °, tenemos;
270 ° + 60 + x = 360
x = 360 - 270 - 60 = 30 °
write the next three multiples of 9
36,
Answer:
45,54,63
Step-by-step explanation:
The multiples of 9 are
9,19,27,36,45,54,63,72,81
The three multiples are 36 are
45,54,63
Answer:
9, 36, 45, 54, 63
Step-by-step explanation:
What is the area of the yard?
Answer:
256
Step-by-step explanation:
Assuming that the length of his garage is the longer dimension (16), the area of the square yard must be 16*16=256 square units. Hope this helps!
you have a 5-inch by 7-inch picture that you framed. When you hung the picture, you found that the entire area is 69.56 in. What is the width of the frame?
Answer:
d. 2.4 in
Step-by-step explanation:
So initially w/o frame the area was 5 x 7 = 35 sq in.
Now we have to add the width of the frame to both dimensions.
(5+w)(7+w) = 69.56 sq in
35 + 7w + 5w + w² = 69.56
w² + 12w + 35 = 69.56
w² + 12w - 34.56 = 0
I use the quadratic formula to solve this (x = -b±√b²-4ac / 2a). I cheat by using a quadratic program on the calculator :,)
w = 2.4
w = -14.4
Since we can't have a negative width, the answer must be w = 2.4 inches.
You can also just plug the answer choices one-by-one into the calculator with guess-and-check because this is multiple choice.
Answer: d) 2.4 inches
Step-by-step explanation:
Let x represent the width of the frame
Then the area of the frame is:
(x + 5)(x + 7) = 69.56
Rewrite it in Standard form of a quadratic equation:
x² + 12x + 35 = 69.56
x² + 12x - 34.56 = 0
Use Quadratic Formula to solve for x:
[tex]x=\dfrac{-b+\sqrt{b^2-4ac}}{2a}\\\\\\x=\dfrac{-12+\sqrt{12^2-4(1)(-34.56)}}{2(1)}\\\\\\x=\dfrac{-12+\sqrt{282.24}}{2}\\\\\\x=\dfrac{-12+16.6}{2}\\\\\\x=\dfrac{4.8}{2}\\\\\\x=\large\boxed{2.4}[/tex]
Calving works totally for 3 hours in weekdays and 5 hours in weekends. How many hours does he works in 4 weeks?
A. 36 hours
B. 32 hours
C. 20 hours
D. 12 hours
Answer:
B. 32
Step-by-step explanation:
5+3=8
8×4=32
// have a great day //
HELP PLEASE
18 miles= how many feet
_________feet
Answer:
18 miles= how many feet
____95,040_____feet
Step-by-step explanation:
happy to help ya:)
nothing to do + tired = ????
Answer: Go and do something :)
Step-by-step explanation:
Get off your phone and get the motivation to fo and find something to do for now :)
De los siguientes datos:2;2;4;4;5;6;6;7;7;8, si se cambian los numeros 4 por 5, ¿cuál de las siguientes medidas cambia?
1: moda
2: mediana.
3: media aritmética
A) solo 2
B) solo 3
C) solo 1 y 2
D) solo 1 y 3
E) 1,2,3
Answer:
what is the question I do not understand
Visualise 3.45 bar up to 3 places of decimal
Answer:
That would be 3.455
Step-by-step explanation:
3.45 bar means the 45 at the back is repetitive.
So we have something like;
3.454545454
Now writing this to three decimal places becomes 3.455
Sean is drinking a slushy as fast as he can.
The amount of slushy left in the cup (in milliliters) as a function of time in seconds) is graphed.
How much slushy did sean drink every 5 seconds
Answer:
40 millimetres
Answer:
40
Step-by-step explanation: