Situation:
Find the substance's half-life, in days.
• Round your answer to the nearest tenth.
A 25 gram sample of a substance that's
used for drug research has a k-value of
0.1229.
Enter the correct answer.
N = Noe
-kt
DONE
No = initial mass (at time t = 0)
?
N = mass at time t
k = a positive constant that depends on
the substance itself and on the units
used to measure time
t = time, in days

Answers

Answer 1

Answer:

5.6 days

Step-by-step explanation:

We are given;

Initial Mass; N_o = 25 g

Mass at time(t); N_t = 25/2 = 12.5 (I divide by 2 because we are dealing with half life)

k = 0.1229

Formula is given as;

N_t = N_o•e^(-kt)

Plugging in the relevant values;

12.5 = 25 × e^(-0.1229t)

e^(-0.1229t) = 12.5/25

e^(-0.1229t) = 0.5

(-0.1229t) = In 0.5

-0.1229t = -0.6931

t = -0.6931/-0.1229

t = 5.6 days


Related Questions

plss, help me!!!

Each of four friends orders a sweatshirt from a catalog. There are 16 colors of sweatshirts, 7 of which are all cotton and 9 wich are blend. Each one orders a different color ( no repeats) at random. What is the probability that the friends order only cotton sweatshirts?​

Answers

Answer:  B) 1/52

===========================================================

Explanation:

Let's label the friends as A,B,C,D.

Person A has a probability of 7/16 when it comes to ordering a certain color of cotton sweatshirt.

Then 6/15 is the probability for person B. Note how the 7 and 16 drop by 1 for each. This is because no repeats are allowed. If person A goes for a blue sweatshirt, then person B cannot select blue as well.

Person C's probability is 5/14 and person D has a probability of 4/13

-------------------------

So we have these fractions: 7/16, 6/15, 5/14, 4/13

Once again, we have the numerators and denominators counting down by 1 each time.

Multiplying those fractions gets us...

(7/16)*(6/15)*(5/14)*(4/13)

(7*6*5*4)/(16*15*14*13)

840/43680

(1*840)/(52*840)

1/52

So if you did 52 trials of this, then you should expect about 1 of those trials is where each friend orders a different color cotton sweatshirt.

1/52 = 0.0192 = 1.92% approximately

So this happens about 1.92% of the time.

Find the x of a triangle.

Answers

This triangle is an isosceles triangle because it has two congruent sides. Therefore, the two bottom angles are also congruent. And, the sum of the interior angles of a triangle is 180 degrees.

180 = 104 + (9x - 25) + (9x - 25)

180 = 104 + 18x - 50

180 = 54 + 18x

126 = 18x

x = 7

Hope this helps!

can someone help me with this?​

Answers

Answer:

-64 is the 26th number

it's an arithmetic sequence because the difference between the number is constant : -3

they are all -3 in difference

Step-by-step explanation:

an = a1 + (n-1)d

an = the nᵗʰ term in the sequence

a1=the first term in the sequence

d=the common difference between terms

-64 = 11 + (n - 1)-3

-64=11 -3n+3

-78 = -3n

n = 26

Can someone help me with this math homework please!

Answers

Answer:

1. [tex]x=2[/tex]

2. Simplify by combining like terms

3. [tex]x=1[/tex]

4. [tex]k=0.5[/tex]

5. [tex]y=3[/tex]

Step-by-step explanation:

1. [tex]2.5(6x-4)=10+4(1.5+0.5x)[/tex]

Distribute within the parenthesis

[tex]15x-10=10+6+2x[/tex]

Combine like terms

[tex]15x-10=16+2x[/tex]

Isolate the variable expression by using the addition/subtraction properties of equality

[tex]13x=26[/tex]

Isolate the variable by using the division/multiplication properties of equality

[tex]x=2[/tex]

2. Like terms are always combined as soon as possible but never before the distributive property is applied.

3. You can find the solution by comparing the tables.

4. [tex]6k+10.5=3k+12[/tex]

Apply the addition/subtraction properties of equality

[tex]3k=1.5[/tex]

Apply the division/multiplication properties of inequality

[tex]k=0.5[/tex]

5. [tex]y+3=-y+9[/tex]

Addition/subtraction properties

[tex]2y=6[/tex]

Division/Multiplication properties

[tex]y=3[/tex]

A fruit punch mixture is made of Orange juice, Pineapple juice, and Cranberry juice in a 3:5:7 ratio. How much of each juice type do you need for a 375 ml mixture?

Answers

Answer: a good amount

Step-by-step explanation:

because if you just get a table spoon for all flavour mixtures then wala they are all the same amount -__-------------i is not smart at all srry

You would get a mixture of a really good smoothie Thankyou for the idea

(a+1)(b+2)
please help me!!!

Answers

Answer:

(a + 1) (b + 2 ) = 2a + b + ab + 2

Step-by-step explanation:

[tex](a +1 )(b + 2) \\\\= a( b+ 2) + 1 (b +2) \\\\= ab + 2a + b + 2\\\\=2a + b + ab + 2[/tex]

Answer:

[tex](a + 1)(b + 2) \\ = a(b + 2) + 1(b + 2) \\ = ab + 2a + b + 2[/tex]

Answer ↦ [tex]\boxed{\tt{ab + 2a + b + 2}}[/tex]

Method Used:

↦ Distributive Property.

ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐

Evaluate the expression 2

Answers

2^5 = 32

Hope this helps! :)

Answer:

32

Step-by-step explanation:

[tex]2^{5}[/tex]

= 2 × 2 × 2 × 2 × 2

= 4 × 4 × 2

= 16 × 2

= 32

The cost of having a window fixed is $175 plus $30 per hour of labor. Using h for the number of hours of labor, write an expression that represents the total cost.

Answers

Answer:

175 + 30h

Step-by-step explanation:

Hope this helps

Answer:

total cost = 175+30h

Step-by-step explanation:

Total cost = fixed cost + cost per hour * hours

total cost = 175+30h  where h is the number of hours

a right triangle is 18 inches long and a hypotenuse that is 30 inches long. what is the perimeter, in inches, of this triangle?

Answers

Answer:

The perimeter is 72 inches

Step-by-step explanation:

using the pythagorean theorem we can solve for the missing leg by plugging in the values we know.

[tex]a^{2} + b^{2} = c^{2} \\18^{2} + b^{2} = 30^{2} \\324 + b^{2} = 900\\ b^{2} = 900-324\\b^{2} = \sqrt{576} \\b= 24[/tex]

now you just add the values, 30 + 24 + 18

Evaluate the expression.
32 + 6 x 22-42 - 23

Answers

Answer:

25

Step-by-step explanation:

You need to simplify

.

.

.

.

................... :)

Answer:

D

Step-by-step explanation:

9+24-16+8= 25

Can someone help me with this math homework please!

Answers

Answer:

3. The number of students that rode on each bus

Step-by-step explanation:

The equation they give us is:

2b + 6 = 70

The question already tells us that in this equation:

2 is the 2 buses that the school hired

6 is the 6 leftover kids who couldn't fit on the 2 buses

The question also tells us that the 2 buses only have a total of 64 seats, so 32 seats on 1 bus (64/2 = 32).

So that means b would equal the 32 seats on 1 bus, or the number of students that rode on each bus.

Hope it helps (●'◡'●)

Plz help me I don’t understand

Answers

Answer:

Step-by-step explanation:

Take two points on the line and find the slope.

(1 , 2)  ; (4 , 4)

Slope = [tex]\frac{y_{2}-y_{1}}{x_{2}-x_{1}}\\\\[/tex]

          [tex]=\frac{4-2}{4-1}\\\\=\frac{2}{3}[/tex]

m = 2/3  & (1 , 2)

Slope point form : y - y1 = m(x-x1)

[tex]y - 2 = \frac{2}{3}*(x - 1)\\\\y - 2 =\frac{2}{3}x - \frac{2}{3}\\\\y =\frac{2}{3}x-\frac{2}{3}+2\\\\y = \frac{2}{3}x-\frac{2}{3}+\frac{2*3}{1*3}\\\\y=\frac{2}{3}x-\frac{2}{3}+\frac{6}{3}\\\\y=\frac{2}{3}x+\frac{4}{3}\\\\Multiply \ equation \ by \ 3\\\\3y = 2x + 4\\\\2x - 3y + 4 = 0[/tex]

A boutique was having a 20% storewide sale.Erica bought 2 dresses which originally cost $80 each.How much savings did Erica enjoy?

Answers

Answer: $32

Step-by-step explanation:

Since the boutique was having a 20% storewide sale and Erica bought 2 dresses which originally cost $80 each, therefore the sale for each dress will be:

= $80 - (20% × $80)

= $80 - (0.2 × $80)

= $80 - $16

= $64

Therefore, on each dress Erica saves $16. The amount of savings enjoyed will then be:

= $16 × 2

= $32


(4x^ 8 y^ 4 +2xy^ 2 -2y)-(-7x^ 2 y)^ 3 +6xy^ 2 -2y) place the correct in difference

Answers

29692 and 5927 u got this hashtag girl boss

Quadrilateral A B C D is shown. All sides are congruent. Angle C is a right angle.
Which statements are true regarding quadrilateral ABCD? Check all that apply.

ABCD has congruent diagonals.
ABCD is a rhombus.
ABCD is not a rectangle.
ABCD is not a parallelogram.
ABCD has four congruent angles.

Answers

Answer:

The first one and last one

Step-by-step explanation:

Answer:

1,2,5

Step-by-step explanation:

got it right on edge

Find the area

Help me please

Answers

Answer:

143

Step-by-step explanation:

to find the area we multiply half of the sum of the bases with height

(18+8)/2*11 = 143

Can you please help with this question. Please please

Answers

Answer:

Step-by-step explanation:

5.2*9= 46.8

Do you want to know how to find the answer? :/

Which set of variables below is most likely to have a positive correlation?

A. Amount of miles driven in a car and country in which the car doing the driving was made
B. Amount of miles driven in a car and amount of gasoline left in the gas tank
C. Amount of miles driven in a car and model year of the car used to do the driving
D. Amount of miles driven in a car and amount of gasoline used

Answers

Answer:

D

Step-by-step explanation:

The amount of miles increase and the amount of gasoline used increases

A movie rental store gives free popcorn to every 40th
customer and a free movie rental to every 45th
customer. Which customer was the first to win both​ prizes?

Answers

Answer:

360th customer

Step-by-step explanation:

To find the customer that will receive both the free popcorn and the free movie rental, we have to list the multiples of 40 and 45 until we get a multiple that is the same for both of them.

Multiples of 40: 40, 80, 120, 160, 200, 240, 280, 320, 360, 400, 440

Multiples of 45: 45, 90, 135, 180, 225, 270, 315, 360

360 is the first multiple that is same for multiples of 40 and 45

So the 360th customer will receive both items.

(Sorry if my explanation is hard to understand. I haven't done this kind of math in a while)

Hope it helps (●'◡'●)

50 pts pls help
What is the range of the function shown on the graph above?

Answers

572^ the answer above is correct!!!!!

Answer:

[0, 7]

Step-by-step explanation:

The range is the set of y-values.

The graphed function has its range between 0 and 7, both inclusive.

So the range is:

y ∈ [0, 7]

Carmen likes to ski. The ski resort where she goes to ski got 3.2 feet of snow during a 5 day period. The average daily snowfall for a given number of days is the quotient of the total amount of snow and the number of days. Estimate the average daily snowfall.

Answers

Answer:

0.64 feet or 7.68 inches of snow on average over the 5 days.

Step-by-step explanation:

3.2/5

0.64ft

7.68in.

685 gym members were asked if they use the elliptical machine or treadmill as their primary cardiovascular exercise. 257 said they use the treadmill, 157 said they use the elliptical, and 85 said they use both.

a.) Organize this using a venn diagram (2 marks)

b.) A gym member is chosen from this group. What is the probability that this member uses the treadmill only? (1 mark)

Answers

Given:

Total number of gym members = 685

257 said they use the treadmill, 157 said they use the elliptical, and 85 said they use both.

To find:

a. The venn diagram.

b. The probability that a member uses the treadmill only?

Solution:

(a)

We have,

Total number of gym members = 685

Treadmill user = 257

Elliptical user = 157

Who use both = 85

Only treadmill user is:

[tex]257-85=172[/tex]

Only Elliptical used

[tex]157-85=72[/tex]

Therefore, the venn diagram for the given situation is shown below.

(b)

The member who use treadmill only = 172

Total user = 685

The probability that a member uses the treadmill only is:

[tex]P(\text{Only treadmill})=\dfrac{\text{Only treadmill users}}{\text{Total users}}[/tex]

[tex]P(\text{Only treadmill})=\dfrac{172}{685}[/tex]

Therefore, the probability that a member uses the treadmill only is [tex]\dfrac{172}{685}[/tex].

Covert 1.18 into a fraction

Answers

1 18/100
1 9/50 is the answer

Answer:

13/11

Step-by-step explanation:

| would assume you mean 1.18 recurring, because 1.18 as a fraction is 59/50.

To work out 1.18 recurring, first we ignore the 1.0 and focus on 0.18 recurring.

If x = 0.18 recurring

  100x = 18.18 recurring

  99x = 18

  x = 18/99

     = 2/11

Now, we add on the 1.0 (11/11) to get 13/11

resultado da prova da olimpíadas de matemática​

Answers

I don’t understand this question

Jahlil is 6 inches shorter than 4 times his sister’s height. Jahlil’s height is 70 inches.

Answers

Answer:

x = his sister's height = 19 inches

Step-by-step explanation:

Let

x = his sister's height

Jahlil's height is given by the equation:

4x - 6 = 70

4x = 70 + 6

4x = 76

x = 76/4

x = 19 inches

x = his sister's height = 19 inches

Check:

4x - 6 = 70

4(19) - 6 = 70

76 - 6 = 70

70 = 70

What conclusion would be true given the hypothesis?

Answers

Answer:

4th option

Step-by-step explanation:

If ∠ 1 = ∠ 2 = ∠ 3

Then ∠ 1 = ∠ 3 is true

Answer:

The second one the measure of angle?1 is less then angle 3 is the correct answer.

A student can walk to school in 3/4 of an hour. She can ride to school in 1/6 of that time. What fraction of an hour does it take the student to bike to school?

Answers

Answer:

1/8 of an hour

Step-by-step explanation:

3/4 x 1/6 = 3/24 = 1/8

Hope this helps!

Which graph shows the solution to the system of linear inequalities?

x – 4y < 4

y < x + 1

On a coordinate plane, 2 straight lines are shown. The first solid line has a positive slope and goes through (0, negative 1) and (4, 0). Everything above the line is shaded. The second dashed line has a positive slope and goes through (negative 1, 0) and (0, 1). Everything below the line is shaded.

On a coordinate plane, 2 straight lines are shown. The first dashed line has a positive slope and goes through (negative 1, 0) and (0, 1). Everything above of the line is shaded. The second solid line has a positive slope and goes through (0, negative 1) and (4, 0). Everything above the line is shaded.

On a coordinate plane, 2 straight lines are shown. The first solid line has a positive slope and goes through (0, negative 1) and (4, 0). Everything above the line is shaded. The second solid line has a positive slope and goes through (negative 1, 0) and (0, 1). Everything below the line is shaded.

On a coordinate plane, 2 straight lines are shown. The first solid line has a positive slope and goes through (0, negative 1) and (4, 0). Everything below the line is shaded. The second dashed line has a positive slope and goes through (negative 1, 0) and (0, 1). Everything below the line is shaded.

Answers

Answer:

its the 2nd

Step-by-step explanation:

The graph showing common region to both inequalities represents the solution coordinates that satisfy both inequalities.

What is inequality in mathematics?

In mathematics, an inequality is a relation which makes a non-equal comparison between two numbers or other mathematical expressions.

Given are the following inequalities -

x – 4y < 4

y < x + 1

We have the following inequalities -

x – 4y < 4

y < x + 1

Inequality [1]

x - 4y < 4

x - 4 < 4y

4y > x - 4

y > x/4 - 1

Inequality [2]

y < x + 1

Refer to the graph attached. The common region to both inequalities represents the solution.

Therefore, the graph showing common region to both inequalities represents the solution coordinates that satisfy both inequalities.

To solve more questions on inequalities, visit the link below-

brainly.com/question/26434651

#SPJ2

Someone pls help me ill give out brainliest pls don’t answer if you don’t know

Answers

Answer:

(1/3) r2 =(1/3) r +14

1/6 divided by 83 r + 14

97r

i think...

I hope this helps you!

XoXo Mashayla

Step-by-step explanation:

Suppose that a department contains 10 men and 12 women. How many ways are there to form a committee with six members if it must have the same number of men and women

Answers

Answer:

The number of ways is 26,400 ways

Step-by-step explanation:

Given;

total number of men, M = 10

total number of women, W = 12

number of committees to be formed = 6

If there must be equal gender, then it must consist of 3 men and 3 women.

[tex]The \ number \ of \ ways = 10C_3 \times 12C_3\\\\The \ number \ of \ ways =\frac{10!}{3!7!} \times \frac{12!}{3!9!} \\\\T he \ number \ of \ ways = 120 \times 220 = 26,400 \ ways[/tex]

Therefore, the number of ways is 26,400 ways

Other Questions
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