i have a test and only have an hour please hurry!



90 / 3* (9 +6)=?

Answer:

The correct answer is:

Between 600 and 700 years (B)

Step-by-step explanation:

At a constant decay rate, the half-life of a radioactive substance is the time taken for the substance to decay to half of its original mass. The formula for radioactive exponential decay is given by:

[tex]A(t) = A_0 e^{(kt)}\\where:\\A(t) = Amount\ left\ at\ time\ (t) = 75\ grams\\A_0 = initial\ amount = 1000\ grams\\k = decay\ constant\\t = time\ of\ decay = 2500\ years[/tex]

First, let us calculate the decay constant (k)

[tex]75 = 1000 e^{(k2500)}\\dividing\ both\ sides\ by\ 1000\\0.075 = e^{(2500k)}\\taking\ natural\ logarithm\ of\ both\ sides\\In 0.075 = In (e^{2500k})\\In 0.075 = 2500k\\k = \frac{In0.075}{2500}\\ k = \frac{-2.5903}{2500} \\k = - 0.001036[/tex]

Next, let us calculate the half-life as follows:

[tex]\frac{1}{2} A_0 = A_0 e^{(-0.001036t)}\\Dividing\ both\ sides\ by\ A_0\\ \frac{1}{2} = e^{-0.001036t}\\taking\ natural\ logarithm\ of\ both\ sides\\In(0.5) = In (e^{-0.001036t})\\-0.6931 = -0.001036t\\t = \frac{-0.6931}{-0.001036} \\t = 669.02 years\\\therefore t\frac{1}{2} \approx 669\ years[/tex]

Therefore the half-life is between 600 and 700 years

Answer:

They can make six salsa batches

Step-by-step explanation:

Here, we are told that each salsa batch require 1/4 of a cup of red onions and they have 1 1/2 cups, we want to know the number of batches of salsa that can be made

Mathematically, that would be 1 1/2 divided by 1/4

That is;

3/2 divided by 1/4

Hence;

3/2 * 4/1 = 12/2 = 6

They can make six batches of salsa

Answer:

a

[tex]P(4.00 <  X  <  5.00) =  0.58818  [/tex]  

b

[tex]P(X \ge 5.5) = 0.02564 [/tex]

c

[tex]P(X < 4 ) = 0.27652[/tex]

Step-by-step explanation:

From the question we are told that

   The mean is  [tex]\mu = 4.35[/tex]

    The standard deviation is  [tex]\sigma =  0.59[/tex]

Generally the probability that the amount of cosmic radiation to which a person will be exposed on such a flight is between 4.00 and 5.00 mrem is mathematically represented as  

   [tex]P(4.00 <  X  <  5.00) =  P(\frac{ 4 - \mu }{\sigma} <  \frac{X - \mu}{\sigma} <  \frac{ 5 - \mu }{ \sigma}  )[/tex]

Here [tex]\frac{X - \mu}{\sigma}  = Z  (The \  standardized \  value \  of \  X )[/tex]

=> [tex]P(4.00 <  X  <  5.00) =  P(\frac{ 4 - 4.35 }{0.59} <  Z <  \frac{ 5 - 4.35 }{ 0.59}  )[/tex]

=> [tex]P(4.00 <  X  <  5.00) =  P(-0.59322 <  Z <  1.1017  )[/tex]

=> [tex]P(4.00 <  X  <  5.00) =  P( Z <  1.1017  ) - P(Z < -0.59322)  [/tex]

From the z -table the probability of  ( Z <  1.1017  ) and  (Z < -0.59322)   are

      [tex]P( Z <  1.1017  ) =0.8647[/tex]

and

      [tex]P( Z <  -0.59322 ) =0.27652[/tex]

So

=> [tex]P(4.00 <  X  <  5.00) =  0.8647 - 0.27652  [/tex]    

=>  [tex]P(4.00 <  X  <  5.00) =  0.58818  [/tex]    

Generally the probability that the amount of cosmic radiation to which a person will be exposed on such a flight is  At least 5.50 mrem is mathematically represented as

     [tex]P(X \ge 5.5) = 1- P(X < 5.5)[/tex]

Here

      [tex]P(X < 5.5) =  P(\frac{X - \mu }{\sigma}  <  \frac{5.5 - 4.35}{0.59}  )[/tex]

      [tex]P(X < 5.5) =  P(Z< 1.94915) [/tex]

From the z -table the probability of (Z< 1.94915) is  

     [tex]P(Z< 1.94915) = 0.97436[/tex]

So

       [tex]P(X \ge 5.5) = 1- 0.97436[/tex]

=>     [tex]P(X \ge 5.5) = 0.02564 [/tex]

Generally the probability that the amount of cosmic radiation to which a person will be exposed on such a flight is less than 4.00 mrem is mathematically represented as

    [tex]P(X < 4) =  P(\frac{X - \mu }{\sigma}  <  \frac{4 - 4.35}{0.59}  )[/tex]

      [tex]P(X < 4) =  P(Z< -0.59322) [/tex]

From the z -table the probability of (Z< 1.94915) is  

     [tex]P(Z< -0.59322) = 0.27652[/tex]

So

       [tex]P(X < 4 ) = 0.27652[/tex]

Answer:

3768068

Step-by-step explanation:

idk how i just googled a pattern analyzer

The next number in the sequence is 2420484

Given: The sequence of numbers 1, 24, 816, 3264, 12825, 651210

To find: The next number in the sequence

First we note that the number of digits in each term of the sequence increases by one and is equal to the place of the term in the sequence. So, the first term has 1 digit, the second term has 2 digits, the third term has 3 digits and so on.

The next term in the sequence should be the seventh term of the sequence and should have 7 digits.

Now, the geometric sequence starting from 1 and having a factor of 2 is given by,

1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096,...

Now, we note that the terms of the given sequence are obtained by concatenating the digits of consecutive terms of the above sequence until the required number of digits are reached.

So, the first term, which has a limit of 1 digit, becomes 1

The second term, which has a limit of 2 digits, becomes the concatenation of 2 and 4, that is, 24

The third term, which has a limit of 3 digits, becomes the concatenation of 8 and 16, that is, 816

The fourth term, which has a limit of 4 digits, becomes the concatenation of 32 and 64, that is, 3264

The fifth term, which has a limit of 5 digits, becomes the concatenation of 128 and 256. However, since the fifth term has a limit of 5 digits. So, the term becomes 12825 with the 6 being carried over to the next term.

The sixth term, which has a limit of 6 digits, becomes the concatenation of 6 (carried over from the previous term), 512 and 1024. However, since this term has a limit of 6 digits. So, the term becomes 651210 with the 24 being carried over to the next term.

So, the next term (seventh term) should be the concatenation of 24 (carried over from the previous term), 2048 and 4096. However, this term should have a limit of 7 digits. So, the term should be 2420484 with 096 being carried over to the next term.

So, the next number should be 2420484.

Learn more about patterns of numbers here:

https://brainly.com/question/14060365

Answer:

Step-by-step explanation:

sea level means negative so it have to be C -0.5 foot

problem solved

Answer:

512

Step-by-step explanation:

8x8x8 is equals to 512

Answer:

Step-by-step explanation:

The first equation is the weights of the rabbit and the ferret together which is

r + f = 7.

The second equation puts the weight of the ferret in terms of the rabbit. If the ferret's weight is 2 pounds more than the rabbit, then

f = r + 2 (the word "is" means equals). Since we know what f is equal to, we will sub it into the first equation and solve for r:

r + (r + 2) = 7 and

2r + 2 = 7 and

2r = 5 so

r = 2.5 pounds.

A rabbit weights 2.5 pounds and the ferret weights 7 - 2.5 which is 4.5 pounds.

Answer:

Angle RQT and Angle RQO

Step-by-step explanation:

These angles share the common vertex of Q and the common side of RQ

Answer:

The first option.

Step-by-step explanation:

The way I always remember adjacent angles is they are kinda beside each other.

Answer:

Step-by-step explanation:

Given: $1.99 as the fee per book (slope) & fixed fee of $3 (y-intercept)

The function can be written out f(x) = 1.99x + 3.

Express the value of f(x) for x = 0.

This would cancel out the slope, giving us a horizontal line on (0, 3).

f(0) = 1.99(0) + 3

f(0) = 3

You can try to graph the function using a software or by hand.

The graph is continuous because the x-values can have any input as a point.

Answer:

The probability that the proportion of flops in a sample of 701 released films would differ from the population proportion by greater than 7% is 0.00001

Step-by-step explanation:

We are given;

Probability that the films released are flops = 9% = 0.09

Sample size = 701

Formula for standard deviation is;

σ = √(p(1 - p)/n)

σ = √(0.09(1 - 0.09)/701)

σ = √0.0001168331

σ = 0.0108

We want to find the probability that the proportion of flops in a sample of 701 released films would be greater than 7%.

Thus, it means x - μ = 7% = 0.07

Z-score formula here is;

z = (x - μ)/σ

z = 0.07/0.0108

z = 6.4815

From online p-value from z-score calculator attached using; z = 6.4815, Nominal significance level = 0.05, two tailed distribution, we have;

P-value = 0.00001

Answer:

The owner's total profit is $120,000.

Step-by-step explanation:

Assume that:

X₁ = contract is assigned to firm 1

X₂ = contract is assigned to firm 2

The sample space for assigning the two contracts is:

S = {(I, I), (I, II), (I, III), (II, I), (II, II), (II, III), (III, I), (III, II) and (III, III)}

There are total of 9 possible combinations.

So, the probability of selecting any of the combination is, 1/9.

Compute the probability distribution of X₁ and X₂ as follows:

X₁      P (X₁)                      X₂        P (X₂)

0        4/9                        0           4/9

1         4/9                        1            4/9

2         1/9                        2           1/9

Compute the expected values of X₁ and X₂ as follows:

[tex]E(X_{1})=\sum X_{1}\cdot P(X_{1})\\\\=(0\times\frac{4}{9})+(1\times\frac{4}{9})+(2\times\frac{1}{9})\\\\=\frac{6}{9}\\\\=\frac{2}{3}[/tex]               [tex]E(X_{2})=\sum X_{2}\cdot P(X_{2})\\\\=(0\times\frac{4}{9})+(1\times\frac{4}{9})+(2\times\frac{1}{9})\\\\=\frac{6}{9}\\\\=\frac{2}{3}[/tex]

It is provided that each contract will yield a profit of $90,000.

Compute the owner's total profit as follows:

[tex]\text{Total Profit}=\text{Profit}\times [E(X_{1})+E(X_{2})][/tex]

                   [tex]=90000\times[\frac{2}{3}+\frac{2}{3}]\\\\=120000[/tex]

Thus, the owner's total profit is $120,000.

Answer:

The probability that a randomly chosen part has diameter of 3.5 inches or more is 0.9525

Step-by-step explanation:

[tex]Mean = \mu = 3.25 inches[/tex]

Standard deviation = [tex]\sigma = 0.15 inches[/tex]

We are supposed to determine the probability that a randomly chosen part has diameter of 3.5 inches or more

[tex]P(Z \geq 3.5)=1-P(z<\frac{x-\mu}{\sigma})\\P(Z \geq 3.5)=1-P(z<\frac{3.25-3.5}{0.15})\\P(Z \geq 3.5)=1-P(z<-1.67)[/tex]

Refer the z table for p value

[tex]P(Z \geq 3.5)=1-0.0475\\P(Z \geq 3.5)=0.9525[/tex]

Hence  the probability that a randomly chosen part has diameter of 3.5 inches or more is 0.9525

Answer:

59

Step-by-step explanation:

Answer:

i believe the answer is C

Step-by-step explanation:

i dont know its just what i would choose im not the smartests in math

Answer:

The additional wells for maximum amount of oil per day is 3 wells.

Step-by-step explanation:

Given;

initial number of wells, n = 6

total production, T = 1800

average production per well, = 1800/6 = 300 barrels per day

Let the additional well = y

total number of wells after optimization = 6 + y

new production per well = 300 - 25y

new total production = (6+y)(300-25y)

t = 1800 - 150y + 300y - 25y²

t = 1800 + 150y - 25y²

dt / dy = 150 -50y

for maximum value, dt/dy = 0

150 - 50y = 0

50y = 150

y = 150 / 50

y = 3

Therefore, the additional wells for maximum amount of oil per day is 3 wells.

33 additional wells should be drilled, reaching 39 wells, to obtain the maximum amount of oil per day.

Given that an oilfield contains 6 wells that produce a total of 1,800 barrels of oil per day, and for each additional well that is drilled, the average production per well decreases by 25 barrels per day, to determine how many additional wells should be drilled to to obtain the maximum amount of oil per day, the following calculation must be performed:

Therefore, 33 additional wells should be drilled, reaching 39 wells, to obtain the maximum amount of oil per day.

Learn more in https://brainly.com/question/13581736

Answer:

The average set of 2 gift cards will price at $140

Step-by-step explanation:

If there are 15 in the group, and there is a total of $1050, this means that the individual prices will be;

$1050/15 = $70

So each gift card in the group cost $70

So the price of 2 will be 2(70) = $140

Answer: 0

Step-by-step explanation:

The common denominator is 6

-2/3 = -4/6

-4/6 + 4/6 = 0

Answer:

Step-by-step explanation:

Area of a square = Length * Length

Given

Length of garden = 7.4feet

Area of the square = 7.4 * 7.4

Area of the square  = 54.76 ft²

Hence the area of the garden is 54.76 ft²

Answer:

Question 1: She had $352 in her wallet

Question 2: The percent of the trout were the tiger trout is 45%

Step-by-step explanation:

Question 1:

∵ Carmen spent $88 at the mall

∵  The money she spent was 25% of the total amount she had in her wallet

→ Assume that the amount she had in her wallet is $x

∴ 25% of x = 88

→ Change 25% to decimal by divide it by 100

∵ 25% = [tex]\frac{25}{100}[/tex] = 0.25

∴ 0.25 × x = 88

∴ 0.25x = 88

→ Divide both sides by 0.25 to find x

∴ [tex]\frac{0.25x}{0.25}=\frac{88}{0.25}[/tex]

∴ x = 352

∵ x represents the total amount she had in her wallet

∴ She had $352 in her wallet

Question 2:

∵ Kendrick caught 22 rainbow trout and 18 tiger trout while fishing

  last month

∴ The number of rainbow trout = 22

∴ The number of tiger trout = 18

→ To find the percent of tiger trout divide its number by the total number

   of trout, then multiply the result by 100%

∵ The total number of the trout = 22 + 18 = 40

∴ The percent of the tiger trout = [tex]\frac{18}{40}[/tex] × 100%

∴ The percent of the tiger trout = 45%

∴ The percent of the trout were the tiger trout is 45%

His per cent error is 16.¯^6%

Explanation:

Trent estimated his time to be 90m but the Actual time was 75m

Error was 90m−^75m=15m

A Fractional error was then 15m90m

So % error is 1590 ×100=1006%=16.¯^6%

Answer:

His percent error is 16.6 %

Step-by-step explanation:

Trent estimated hie time to be 90m

Actual time was 75m

Error was 90m - 75m = 15m

Fractional error was then 15m/90m (divide)

So % error is 15/90 times 100 = (100/6)% = 16.6%

Answer:

a) σ  = 0,1612

b) P [ 11,75 < X < 12,35] = 0,92,44   or    92,44 %

Step-by-step explanation:

NOTE: I assume the unusable length s 11,5 and less

a) For a normal distribution, the probability of P = 0,01 corresponds to z(score) =  -3,1 then:

- 3,1 = ( X - μ₀ ) / σ

- 3,1 = (11,5 - 12 )/ σ

-3,1 = - 0,5 / σ

σ  = 0,1612

b) If σ = 0,1612

P [ 11,75 < X < 12,35]

z₁ (score)  = ( 11,75 - 12 ) / 0,1612

z₁  = - 0,25/ 0,1612

z₁  = -1,55

From z table  P [ 11,75 < X] = 0,0606

z₂ (score) = ( 12,35 - 12) / 0,1612

z₂ = 0,35 / 01612

z₂ = 2,17

From z table  P [ X < 12,35] = 0,9850

Finally P [ 11,75 < X < 12,35] = 0,9850 -  0,0606

P [ 11,75 < X < 12,35] = 0,92,44   or    92,44 %

Answer:

More than

Step-by-step explanation:

Answer:

More

Step-by-step explanation:

Answer:

Hi, there--

THE PROBLEM:

We invested $10,000 in 2 bank accounts. One account earns 14% per year the other earns 8%

per year. How much did we invest into each account if after the first year, the combined

interest from the 2 accounts is $1238?

A SOLUTION:

Define Variables:

Let x be the amount you originally invested in the first account.

Let y be the amount you originally invested in the second account.

Write Expressions and Equations:

Since you invested a total of $10,00 in two accounts. An equation that represents this is

x + y = 10000

One account (say the first one) earns 14% per year. Recall that the decimal form of 14% is

0.14. An expression for the amount of interest you earn after the first year in this account is

0.14x.

The other account earns 8% per year. The decimal representation of 8% is 0.08. The amount

of interest you earn after one year in this account is 0.08y.

The combine interest from both account after one year is $1238. An equation representing

the total interest earned is

0.14x + 0.08y = 1238

Now we have a system of two equations with two variables. We can solve for x and y. Rewrite

the first equation in "y=" form.

x + y = 10000

y = 10000 - x

Substitute 10000-x for y in the second equation.

0.14x + 0.08y = 1238

0.14x + 0.08(10000 - x) = 1238

Solve this equation for x. Use the Distributive Property to clear parentheses.

0.14x + 800 - 0.08x = 1238

Combine like terms (0.14x-0.08x is 0.06x).

0.06x + 800 = 1238

Subtract 800 to both sides to isolate x on the left.

0.06x = 1238 - 800

0.06x = 438

Divide both sides of the equation by 0.06.

x = 438/0.06

x = 7300

In the context of this problem, x=7300 means that you invested $7300 in the first account.

Since you invested a total of $10000, you invested 10000-7300=$2700 in the second account.

Check your work by verifying that these amounts will yield the correct amount of interest.

Substitute 7300 for x and 2700 for y in the interest equation.

0.14x + 0.08y = 1238

0.14(7300) + 0.08(2700) = 1238

1022 + 216 = 1238

1238 = 1238

Check!

Hope this helps! Feel free to email if you have any questions about the

Answer:

ab = 1

Step-by-step explanation:

A Reciprocal of a number is a number which when multiplied by the original number yields the multiplicative number, 1.

So the reciprocal of x would be x⁻¹ or ¹⁄ₓ

The information we are given states that the sum of the two non-zero numbers a and b equals the sum of their reciprocals.

So we can write this into an equation and solve,

(See image)

Once we solve, we get the equation (ab-1)(a+b) = 0

We are given info that a+b≠0

So for the above equation to be true, ab-1 has to equal 0

For this to be true, the product ab must equal 1

Answer: 31

Step-by-step explanation: long division

Answer:

7739.5

Step-by-step explanation:

Answer:25p+45<480

Step-by-step explanation:

Answer: 25p+45<480

Step-by-step explanation:

Answer:

There are 35 girls in the recycling club

Step-by-step explanation:

4 boys : 7 girls

20 boys : x girls

In order to get to 20, you have to multiply 4 by 5, so multiply 5 to 7 for the girls.

7(5) = 35

There are 35 girls

Answer:

(a)0.625s (b)1.569s

Step-by-step explanation:

it's Physics, not Math.

Details of the answer:

https://brainly.com/question/13741614

Answer:

With this algebraic representation of physics, we can also apply the mathmatical concept of quadratics to derive the components from this function. You can use the line of symmetry: x = -b/2a. To find the minimum or maximum height because of its association with the vertex. This function is in the standard quadratic form: ax^2 + bx + c where x is t. According to this instance, a being -16, b being 24, and c being 8. t = -b/2a → -24/-32 = 3/4 which also represents the maximum value because a is negative so it is opening downward.

To find the max height, substitute the value of x back into the equation f(3/4) = -16(3/4)^2 + 24(3/4) + 8 →

-9 + 18 + 8 = 17ft [maximum height]

We already solved for the time (x) in terms of t which is 3/4 sec [time of maximum height].

Answer:

(a) What was the total of accounts written off during the first 11 months?

(b) As the result of a comprehensive analysis, it is determined that the December 31, 2010, balance of the Allowance for Bad Debts account should be $9,450. Show the adjustment required in the journal entry format.

a. Bad debt written off = Opening Balance in bad debt allowance account +  Bad debt expense recognized during the period - Closing balance in bad debt allowance account

Bad debt written off = $13,966 + $21,297 - $9,797

Bad debt written off = $25,466

Therefore, the total of accounts written off during the first 11 months is $25,466

b. Date  Description and Explanation     Debit     Credit

31-Dec   Allowance for bad debts             $347

              ($9,797  - $9,450)

                     Bad debt expenses                              $347

                      ($9,797  - $9,450)

               (To record adjustment of allowance of bad debt account)