About 92 days are taken for 90 % of the material to decay.
The mass of radioisotopes ([tex]m[/tex]), measured in milligrams, decreases exponentially in time ([tex]t[/tex]), measured in days. The model that represents such decrease is described below:
[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (1)
Where:
[tex]m_{o}[/tex] - Initial mass, in milligrams.[tex]m(t)[/tex] - Current mass, in milligrams.[tex]\tau[/tex] - Time constant, in days.In addition, the time constant is defined in terms of half-life ([tex]t_{1/2}[/tex]), in days:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (2)
If we know that [tex]m_{o} = 85\,mg[/tex], [tex]t_{1/2} = 27.7\,d[/tex] and [tex]m(t) = 8.5\,mg[/tex], then the time required for decaying is:
[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex]
[tex]\tau = \frac{27.7\,d}{\ln 2}[/tex]
[tex]\tau \approx 39.963\,d[/tex]
[tex]t = -\tau \cdot \ln \frac{m(t)}{m_{o}}[/tex]
[tex]t = -(39.963\,d)\cdot \ln \frac{8.5\,mg}{85\,mg}[/tex]
[tex]t\approx 92.018\,d[/tex]
About 92 days are taken for 90 % of the material to decay.
We kindly invite to check this question on half-life: https://brainly.com/question/24710827
The chances that you will be ticketed for illegal parking on campus are about 1/3. During the last nine days, you have illegally parked every day and have NOT been ticketed (you lucky person!). Today, on the 10th day, you again decide to park illegally. The chances that you will be caught are:
The required probability of getting caught on the 10th day is 3/5.
What is probability?Probability can be defined as the ratio of favorable outcomes to the total number of events.
Here,
Probability of getting caught in 9 days
= [1 - 1/3]*9=6
The probability of getting on the tenth day is given as,
= 6/10
=3/5
Thus, the required probability of getting caught on the 10th day is 3/5.
Learn more about probability here:
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Jane needs to make a four-letter password. If the first letter has to be a vowel, how many possibilities are there to choose from where y is not a vowel
The number of possibilities for Jane for making the four letter password (either upper case or lower case) with first letter being a vowel is 1406080
What is the rule of product in combinatorics?If a work A can be done in p ways, and another work B can be done in q ways, then both A and B can be done in [tex]p \times q[/tex] ways.
Remember that this count doesn't differentiate between order of doing A first or B first then doing other work after the first work.
Thus, doing A then B is considered same as doing B then A
We need to find the number of ways a four letter password can be made The first letter is fixed to be a vowel.
There are 10 vowels (5 of lowercase and 5 of upper case).
Thus, 10 ways of choosing the first letter.
Second letter can be any of the 52 letters(26 of lowercase and 26 of uppercase).
Similarly, third and fourth letter can be any of the 52 letters.
Thus, using the product rule, the number of ways of making the four letter password is:
[tex]N = 10 \times 52 \times 52 \times 52 = 1406080[/tex]
(the answer can be different if we consider only either lowercase letters or only upper case letters. In those cases, there would be [tex]5 \times 26^3 = 87880[/tex] ways to make such passwords).
We used product rule, since we wanted to do the choosing of all the four letters for password, and we knew the number of ways each of them can be done individually.
Thus, the number of possibilities for Jane for making the four letter password (either upper case or lower case) with first letter being a vowel is 1406080
Learn more about rule of product combinations here:
https://brainly.com/question/2763785
If 12 inches = 1 foot, and 3 feet = 1 yard, how many inches are there in 2.5 yards? step by step
5/6 divided by 2 =?
Need answer soon!!
Answer:
0.416666667
Step-by-step explanation:
(winks and runs off)
Answer:
5/12
Step-by-step explanation:
5/6÷2
5/6÷2/1
5/6•1/2
5/12
a square has a shaded part with 7cm and 4cm and 40 cm. workout the percentage of the are inside the square that is shaded
Answer:
68
Step-by-step explanation:
You multipliy 7x4 and you get 28 now you add the 40+28=68.
PLEASE HELP!!!!!!!!!!!!!!!!!!!!
Answer:
I think it's c
Step-by-step explanation:
because that looks like a good answer.
What function represents the next graph?
Answer:
Option 1: y = (x - 2)² + 2
Step-by-step explanation:
Given the vertex, (2, 2), of an upward-facing parabola, and using the y-intercept of the graph, (0, 6):
Definitions:The vertex form of the quadratic equations is:
y = a(x - h)² + k
where:
(h, k) is the vertex.
The value of h represents the horizontal translation of the graph. h > 0 represents the horizontal shift of the graph h units to the right. h < 0 shifts the graph |h | units to the left. The value of k represents the vertical translation of the graph. k > 0 shifts the graph k units upward. k < 0 shifts the graph |k | units down.The sign of a determines the direction of the graph's opening. The value of a also determines the vertical stretch or shrink of the graph.
If a is positive (or a > 1), then the graph opens upward. The value of a > 1 also represents the vertical stretch of the graph. If a is negative (or a < 0), then the graph opens down.The value of 0 < a < 1 represents the vertical shrink or compression of the graph. Solution:Substitute the values of the vertex (2, 2) and the y-intercept, (0, 6) into the vertex form to solve for the value of the coefficient, a:
y = a(x - h)² + k
6 = a(0 - 2)² + 2
6 = a(-2)² + 2
6 = 4a + 2
Subtract 2 from both sides
6 - 2 = 4a + 2 - 2
4 = 4a
Divide both sides by 4 to solve for a :
[tex]\displaytext\mathsf{\frac{4}{4} \:=\frac{4a}{4}}[/tex]
a = 1
Quadratic Equation in Vertex Form:Therefore, given the vertex, (2, 2) and a = 1, the quadratic equation in vertex form is: y = (x - 2)² + 2, thereby matching Option 1.
Megan spent half of her paycheck on an iPad. Over the weekend she earned $12 from babysitting. If she has $514.50 now. Write and equation and solve to find out how much was her paycheck
Solve each inequality
-5y-2<8
Answer:
y > -2
Step-by-step explanation:
-5y-2<8
= -5y<8+2
= -5y<10
= y > 10/-5
∴ y > -2
Note: Anytime you multiply or divide both sides of the inequality, you must “flip” or change the direction of the inequality sign.
simplify 16v²÷2v²tlA
Hello
just a second
people reading this please complete because you will help me a lot.
I am an Indian girl my name is Lamer and am 13 years old.
I Just got this new device after working at a farm for 2 years.
I used to use brainly at my friend device she had money to buy brainly plus.
I cant please help me get points so I can get good marks and my dad let me complete my education instead of getting married.
I need help please
Which value is the closest to
0.9 • 997
a. 1,000
b. 81
c. 10,000
d. 10
Answer with supporting work:
Kelly has 15 blue bracelets and 12 green bracelets. What is the ratio of Kelly’s blue bracelets to green bracelets?
Answer:
5:4
Step-by-step explanation:
Answer:
5:4
Step-by-step explanation:
To simplify the ratio 15:12, we find the greatest common divisor of 15 and 12, and then we divide 15 and 12 by the greatest common divisor.
The greatest common divisor that you can use to simplify 15:12 is 3. Which means the answer to ratio 15:12 simplified is:
5:4
Could someone please help?
Answer:
snap for secsy pics
Step-by-step explanation:
cat.lover
what is the improper fraction 2 7/8what is the improper fraction 8 2/3
Answer:
1. 23/8
2.26/3
Step-by-step explanation:
6 less than the quotient of 4 and a number
Answer:
4/n subtracted by 6 or the third option
Step-by-step explanation:
What is the probability that out of 125 babies born, at least 50 will be girls?
Assume that boys and girls are equally probable, and round your answer to the nearest tenth of a percent.
A. 70.4%
B. 99.0%
C. 10.5%
D. 51.2%
You're answer would be 99.0%.
Whoever answers first gets 5 stars, and a thanks. And if possible a brainliest
Answer:14.518
Step-by-step explanation:
how do I solve this linear inequality?
5x - 7 > 4x + 8
Step-by-step explanation:
just like an equation.
5x - 7 > 4x + 8 | -4x + 7
x > 15
and that is your result.
in contrast to an equation, an inequality delivers a range as result and not a single point.
Answer:
[tex]\huge\boxed{\sf x > 15}[/tex]
Step-by-step explanation:
5x - 7 > 4x + 8
Subtract 4x to both sides, and Add 7 to both sides
5x - 4x > 8 + 7
x > 15
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807how do i simplify these?
. X x X x X
.Y x Y x Y x Y x Y
Hello!
X*X*X=X times X times X = X³
Y*Y*Y*Y*Y=Y times Y times Y times Y times Y= Y⁵
Hope it helps you! :)
Let me know if you have any query or need further explanation. :)
~A determined gal
[tex]MagicalNature[/tex]
another mathh question
where is the Question!!!
can you plz give me brainliest I really need it
Your question is incomplete.
Please if you need help I will try to help you :)
Have a Good Day.
this is due in less the 30 minutes and this is my last question on the assignment please help and show work. will give brainliest
Answer:
22,100
Step-by-step explanation:
Answer:
the answer in 18,300
Step-by-step explanation:
2 x 3 5/8= 7 1/4
7 1/4 +1 9/10= 9 3/20
9 3/20 / 2= 18 3/10
18 3/10 x 1000=18,300
find the slope of the line through these pair of points. (17, –6), (–11, 7)
m = (Y2 - Y1)/(X2 - X1)
m = (7 - (-6))/(-11 - 17)
m = (7 + 6)/(-28)
m = 13/(-28) = -(13/28)
(04.01 MC) Which set of points includes all of the solutions for y = negative four fifths times x plus two?line going through 0 comma 2 and 5 comma negative 2 Group of answer choices (15, 10), (0, 2), and (−10, 10) (−10, 10), (−5, 6), (0, 2), (5, −2), (10, −6) (x, y) for all real numbers (x, negative four fifths times x plus two) for all real numbers
The solutions of a function are the true values of the function
The solutions are: (0,2), (5,-2), (-10, 10) and (-5,6)
The function is given as:
[tex]\mathbf{y = -\frac 45 x + 2}[/tex]
From the question, we understand that the line of the equation passes through points (0,2) and (5,-2)
This means that:
(0,2) and (5,-2) are solutions of the equation
Other possible solutions include (-10, 10) and (-5,6)
This is true because, when these values are substituted in the equation, the result of the equation is true
Hence, the true options are:
(0,2), (5,-2), (-10, 10) and (-5,6)
Read more about solutions of equations at:
https://brainly.com/question/545403
What is the equation in slope-intercept form of the line that passes through the point (5, 0) and is parallel to the line represented by =2.2+1.2
y
=
2.2
x
+
1.2
.
Group of answer choices
=−2.2+11
y
=
−
2.2
x
+
11
=2.2−11
y
=
2.2
x
−
11
=−2.2−5
y
=
−
2.2
x
−
5
=2.2+5
Can you please answer this world problem? And please don't mind the numbers on top.
Answer: 5 1/15 feet
Step-by-step explanation:
For this you have to add fractions.
First find a common denominator between the factions which can be will turn into 15.
The fraction is now: 1 10/15 + 3 6/15
Now that the denominator is the same add the fractions.
1 10/15 + 3 6/15 = 5 1/15
Make the answer negative since its under sea level
Answer = -5 1/15 feet
Also need this answer. Thank you so much!!!!!!!!
Answer:
5
Step-by-step explanation:
h(w)=2(1)+3
h(w)=2+3
h(w)=5
please give me brainliest think took some thinking
Plzzzzzz help one more time
Steve had 1400 pesos. Heloaned 500 pesos to a friend, spent 310 pesos, and received his800 pesos paycheck from work. How much money does he have now?
Answer:
1390
Step-by-step explanation:
1400- 500= 900 (loaned → deduction→ meaning subtraction)
900- 310 = 590 (spent→ deduction→ meaning subtraction)
590 + 800 = 1390 (received→ gained→ addition)
Anna starts a fixed deposit with $178000, the bank offers 9.5% per year simple interest for 8 months. she has the option of restarting the investment using the interest earned as principal or cashing out at the end of the 8 months, (A) Calculate the interest due after 8 months. (B) if she restarts the investment into a new one calculate the total value of the investment at the end of the second 8 months
Using simple interest, we have that:
A) The interest due after 8 months is $11,272.33.
B) The total value of the investment will be of $189,986.24.
The amount of interest earning using simple interest, after t years, with an yearly interest rate of i and an initial investment of P is given by:
[tex]E = Pit[/tex]
In this problem:
Deposit of $178,000, hence [tex]P = 178000[/tex].Interest rate of 9.5% per year, hence [tex]i = 0.095[/tex].8 months, the time is in years, hence [tex]t = \frac{8}{12} = \frac{2}{3}[/tex]Item a:
[tex]E = Pit[/tex]
[tex]E = 178000(0.095)\frac{2}{3} = 11272.33[/tex]
The interest due after 8 months is $11,272.33.
Item b:
For the second interest, we consider [tex]P = 11272.33[/tex], hence:
[tex]E_2 = Pit[/tex]
[tex]E_2 = 11272.33(0.095)\frac{2}{3} = 713.91[/tex]
The total value will be composed by:
The initial deposit of $178,000.The first interest of $11,272.33.The second interest of $713,91.Hence, it will be:
[tex]T = 178000 + 11272.33 + 713.91 = 189986.24[/tex]
The total value of the investment will be of $189,986.24.
A similar problem is given at https://brainly.com/question/13176347
Find the length of the diagonal in rectangle using image 3353
Answer:
65
Step-by-step explanation:
c=a2+b2=332+562=65