Look at the image. Could someone please help me out? Only question B Thank you! WILL GIVE BRAINLYEST​

Answer:

2.5 half-lives

Step-by-step explanation:

Find [tex]t_{h}[/tex] in [tex]N(t)=N_{0}e^{-kt}[/tex] given [tex]N(t) = 2, N_{0} =64,t=\frac{25}{2}[/tex]

[tex]N(t)[/tex] is the amount after the time [tex]t[/tex], [tex]N_0[/tex] `is the initial amount, [tex]t_{h}[/tex] is the half-life

We know that after half-life there will be twice less the initial quantity:

[tex]N(t_{h})=\frac{N_{0} }{2}=N_{0}e^{kt_{h} }[/tex].

Simplifying gives [tex]\frac{1}{2} =e^{-kt_h} or k = -\frac{In(\frac{1}{2}) }{t_{h} } .[/tex]

Plugging this into the initial equation, we obtain that [tex]N(t)=N_{0}e^\frac{In(\frac{1}{2}) }{t_{h} }[/tex]or [tex]N(t)= N_{0} (\frac{1}{2})^\frac{t}{t_h}.[/tex]

Finally, just plug in the given values and find the unknown one.

From [tex]2=64(\frac{1}{2})^\frac{\frac{25}{2} }{t_h}[/tex], we have that [tex]t_h[/tex] = [tex]\frac{25 In (2)}{2 In (32)\\}[/tex]

So you should get: [tex]t_{h} =\frac{25 In (2)}{2 In (32)\\}=2.5.[/tex]

The number of half-lives that transpired during this time period is equal to 2.5 hours.

Given the following data:

Time = 12.5 hours.

Initial mass = 64 grams.

Remaining mass = 2.0 grams.

Mathematically, the amount of a radiocative element that is remaining after time (t-hours) is given by this formula:

[tex]ln(\frac{A}{A_0} )=ln(\frac{1}{2} )\frac{t}{H}[/tex]

Where:

Substituting the given parameters into the formula, we have;

ln(2/64) = ln(1/2) × 12.5/H

-3.466 = -0.693 × 12.5/H

H = 12.5 × -0.693/-3.466

H = 12.5 × 0.1999

H = 2.5 hours.

Read more on half-life here: https://brainly.com/question/25750315

Answer:

hi how r u today my stranger

Answer:

D-Dipper/////

Step-by-step explanation:

Answer:

24a + 3a

27a

we didn't multiply a since it is addition so it can not be a²

please give brainiest

Answer:

27a

Step-by-step explanation:

Just distribute. First multiply 4 times 6 which would be 24a. 24a+3a would then be 27a ;)

Answer:

0.237/3.5

Step-by-step explanation:

In order to rite 237 m as a fraction of 3.5 km, 237m must be in the same unit as 3.5km

it is necessary to convert, 237m to km

1000m = 1 km

so 237m = 237/1000= 0.237

0.237/3.5

Answer:

Answer as a fraction: 4/15

Answer as a decimal: 0.267

The decimal version is approximate rounded to three decimal places.

Step-by-step explanation:

6 apples, 4 peaches

6+4 = 10 pieces of fruit total

The probability of picking an apple is 6/10 = 3/5

After you pick and eat the apple, there are 10-1 = 9 pieces of fruit left. Also, the probability of picking a peach is 4/9, as there are 4 peaches out of 9 fruit left over.

Multiply out 3/5 and 4/9 to get (3/5)*(4/9) = (3*4)/(5*9) = 12/45 = 4/15

Using a calculator, 4/15 = 0.267 approximately.

Answer:

3

Step-by-step explanation:

f(3) = 3(3)-4

f(3)= 9-4

f(3) = 5

g(2) = (2)

g(2) = 2

f(3)-g(2) = ?

(5) - (2) = ?

(5) - (2) = 3

njjjwer:

jajajajaj

Step-by-step explanation:

Answer:

a) 75%.

b) 84%

c) Within 2 standard deviations from the mean is 95%. The normal distribution has a higher percentage of observations closer to the mean than a non normal distribution, so this percentage is larger.

Step-by-step explanation:

Empirical Rule:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

Chebyshev Theorem:

The Chebyshev Theorem can also be applied to non-normal distribution. It states that:

At least 75% of the measures are within 2 standard deviations of the mean.

At least 89% of the measures are within 3 standard deviations of the mean.

An in general terms, the percentage of measures within k standard deviations of the mean is given by [tex]100(1 - \frac{1}{k^{2}})[/tex].

In this question:

Mean: 6.3 hours

Standard deviation: 1.6 hours

(a) Use Chebyshev's theorem to calculate the minimum percentage of individuals who sleep between 3.1 and 9.5 hours.

3.1 = 6.3 - 2*1.6

9.5 = 6.3 + 2*1.6

Within 2 standard deviations, so the minimum percentage is 75%.

(b) Use Chebyshev's theorem to calculate the minimum percentage of individuals who sleep between 2.3 and 10.3 hours.

How many standard deviations from the mean?

One standard deviation is 1.6

These measures are 10.3 = 6.3 = 6.3 - 2.3 = 4. This is k standard deviations, in which

[tex]k = \frac{4}{1.6} = 2.5[/tex]

The minimum percentage is:

[tex]100(1 - \frac{1}{k^{2}}) - 100(1 - \frac{1}{2.5^{2}}) = 84%[/tex]

So 84%.

(c) Assume that the number of hours of sleep follows a bell-shaped distribution. Use the empirical rule to calculate the percentage of individuals who sleep between 3.1 and 9.5 hours per day.

Within 2 standard deviations from the mean is 95%. The normal distribution has a higher percentage of observations closer to the mean than a non normal distribution, so this percentage is larger.

Answer:

9

Step-by-step explanation:

In Order to gain the mean you would follow the formula:

Total Sum of all Numbers added together / Amount of integers.

In this case, you have 5 numbers 1, 3 , 5 , 2 , x .

I know that the overall sum of all your integers added together must equal 20, as 20 / 5 = 4.

1 + 3 + 5 + 2 = 11.

Therefore x must be 9.

1 + 3 + 5 + 2 + 9 = 20

20 / 5 = 4.

Hope this helps and mark as brainilest if found useful.

Answer:

x = 18.64

Step-by-step explanation:

use tan:

⇒ tan = [tex]\frac{opposite}{adjacent}[/tex]

⇒ tan 46 = [tex]\frac{18}{x}[/tex]

tan of 46 is 1.0355

⇒ 1.0356 = [tex]\frac{18}{x}[/tex]

multiply 18 on both sides

⇒ 1.0355 x 18 = [tex]\frac{18}{x}[/tex] x 18

⇒ 18.64 = x

Answer:

2/3

Step-by-step explanation:

1/2 = 3/6

6 - 5 = 1

1 3/6 - 5/6 = 4/6

4/6 = 2/3

Hope this helped! Have a nice day! Plz mark as brainliest!!!

-XxDeathshotxX

Answer:

Answer is -1.666

Step-by-step explanation:

6*1/2=3

5*5/6=4.1666

Answer:

Her friend got the better deal.

Step-by-step explanation:

For Jillians equation look at

$22.56/4 = $6.39 per CD

For her friends equation look at

$18.45/3 = $6.15 per CD

Jillian's friend got the better deal because she paid less per CD as shown in the equations above.

Answer:

That is wrong bc it says quotient and quotient means a division sign which i dont see on your answer,

Step-by-step explanation:

The correct answer should be...

3/2x

Im srry if wrong (and the "/" means division)

Answer:

15

Step-by-step explanation:

a:b::c:d

a/b=c/d .......(eq 1)

let a=0.2, b=0.5, c=6, d=x

Not put values in eq 1

0.2/0.5 = 6/a

By cross multiplication we get:

0.2xa = 6x0.5

0.2a = 3

Dividing by 0.2 on both sides we get

0.2a/0.2 = 3/0.2

a = 15

Therefore The fourth proportional is 15

Answer:

76.7

Step-by-step explanation:

11.3(3) + 10.7(4) = __ + 42.8

Multiply values

33.9 + 42.8 = __ + 42.8

The missing value is 33.9!

42.8 + 33.9 = 76.7

Answer:

i think its b

Step-by-step explanation:

Answer:

jjjjjk

Step-by-step explanation:

Answer:

The value of 1 is tens =) i hope i help u

Sorry I don't know answer

Answer:

37.5

Step-by-step explanation:

If 50 apples cost 25 then all you need to do is 25 x 1.5 = 37.5

And we know this is correct because 25 divided by 2 is 12.5.

so 12.5 is how much for 25 apples and if you multiply 25 times 3 it is equal to 75 so you need to mutliply 12.5 times 3.

12.5 x 3 = 37.5

Answer:

1549.5

Step-by-step explanation:

Hello There!

Heron's area formula is

[tex]A=\frac{(a)(b)sin(c)}{2}[/tex]

all we have to do is plug in the values

so

[tex]A=\frac{77*41sin79}{2} \\77*41=3157\\3157sin79=3098.997018\\\frac{3098.997018}{2} =1549.498509[/tex]

so the area of the triangle is 1549.498509

our final step is to round to the nearest hundredth

the answer would be 1549.5

Answer:

1610.289units²

Step-by-step explanation:

a=79

b=77

c=43

s=(79+77+43)/2=99.5

by using heron's formula

area of triangle=√{s(s-a)(s-b)(s-c)}

=√{99.5(99.5-79)(99.5-77)(99.5-43)} =1610.289units²

Answer: c is the answer

Step-by-step explanation: the formuals for volume is length x width x height, 6x7x5, which is 210

Answer: C

Step-by-step explanation: Easy, just do length x width x height(l x w h). So, 6x7x5 = 210

Answer:

[tex]m<LMJ = 86[/tex]

Step-by-step explanation:

1. Approach

First, use the sum of angles in a quadrilateral theorem to find the value of the parameter ([tex]x[/tex]). This theorem states that the sum of all angle measures in a quadrilateral is ([tex]360[/tex]). After finding the value of ([tex]x[/tex]), substitute it back into the given value for the ([tex]m<LMJ[/tex]), and solve.

2. Finding ([tex]x[/tex])

Remember, the sum of angle measures in any quadrilateral is 360 degrees, regardless of the quadrilateral type.

Using this knowledge, one can apply it by saying;

[tex]m<K + m<J + m<M + m<L = 360[/tex]

Substitution,

[tex](93) + (76) + (11x-2) + (14x - 7) = 360[/tex]

Combine like terms;

[tex]160 + 25x = 360[/tex]

Inverse operations;

[tex]160 + 25x = 360\\-160\\\\25x = 200\\/25\\\\x = 8[/tex]

3. Finding ([tex]m<LMJ[/tex])

Substitute back in to find the [tex]m<LMJ[/tex]

[tex]11x - 2\\\\x=8\\\\11(8) - 2\\\\88 - 2\\\\86[/tex]

Answer:

m∠M = 86

Step-by-step explanation:

the angles of a quadrilateral equal 360°, adding ∠K and ∠J together we get 169°.

360 - 169 = 191, meaning ∠L and ∠M have to add up to 191.

substitute the values of ∠L and ∠M to make the equation

14x -7 + 11x -2 = 191

combine like terms 14x + 11x and -2 - 7 to get 25x -9 =191

now solve for the value of x by first adding 9 to both sides and then dividing each side by 25 like so:

25x -9 = 191          →      25x = 200    →      25x = 200    → x = 8

     +9     +9                                              /25     /25    

Now put the value of x into the equation for angle M like this:

11(8) -2 = M    and solve, 11×8 = 88, 88 -2 = 86, so the measure of ∠M is 86

Answer- y = - x/2 + 5

Step by step - Replace f (x) with y.

Y = - 2x + 10

Interchange the variables.

x= -2y + 10

Solve for y.

Y= x/2 +5

Answer:

A

Step-by-step explanation:

2.5 x 3.4 = 8.5

Answer:

two solutions work: x = 5 + [tex]\sqrt{19}[/tex] and x = 5 - [tex]\sqrt{19}[/tex]

Step-by-step explanation:

x + 6 ( 1/x ) = 10

x^2 + 6 = 10x

x^2 - 10x + 6 = 0

x = 5 + [tex]\sqrt{19}[/tex], 5 - [tex]\sqrt{19}[/tex]