Answer:
The half-life of this substance is of 569.27 days.
Step-by-step explanation:
Amount of a substance after t days:
The amount of a substance after t days is given by:
[tex]P(t) = P(0)e^{-kt}[/tex]
In which P(0) is the initial amount and k is the decay rate, as a decimal.
Suppose a sample of a certain substance decayed to 69.4% of its original amount after 300 days.
This means that [tex]P(300) = 0.694P(0)[/tex]. We use this to find k.
[tex]P(t) = P(0)e^{-kt}[/tex]
[tex]0.694 = P(0)e^{-300k}[/tex]
[tex]e^{-300k} = 0.694[/tex]
[tex]\ln{e^{-300k}} = \ln{0.694}[/tex]
[tex]-300k = \ln{0.694}[/tex]
[tex]k = -\frac{\ln{0.694}}{300}[/tex]
[tex]k = 0.0012[/tex]
So
[tex]P(t) = P(0)e^{-0.0012t}[/tex]
What is the half-life (in days) of this substance?
This is t for which P(t) = 0.5P(0). So
[tex]0.5P(0) = P(0)e^{-0.0012t}[/tex]
[tex]e^{-0.0012t} = 0.5[/tex]
[tex]\ln{e^{-0.0012t}} = \ln{0.5}[/tex]
[tex]-0.0012t = \ln{0.5}[/tex]
[tex]t = -\frac{\ln{0.5}}{0.0012}[/tex]
[tex]t = 569.27[/tex]
The half-life of this substance is of 569.27 days.
Find x please explanation need it
An elevator is on the twelfth floor it goes down 11 floors and than up 5 floors what floor is the elevator on now
Answer:
The sixth floor
Step-by-step explanation:
Jeannine needs to decide what size to make a rectangular
garden in her yard. The dimensions must be natural numbers.
Jeannine wants the perimeter of her Chapter Reference
garden to be 50 dm. She wants the
width to be an even number of decimeters. How many
different combinations are possible? (Length is always longer than or equal to width.)
Answer:
Total number of possible combinations are 6
Length width
23 dm 2m
21 dm 4 dm
19 dm 6 dm
17 dm 8 dm
15 dm 10 dm
13 dm 12 dm
Step-by-step explanation:
We are given that
Perimeter of rectangular garden=50 dm
Width is even number.
Length is always longer than or equal to width.
Let length of rectangular garden=x
Width of rectangular garden=y
We have to find the possible number of combinations .
Perimeter of rectangular garden=[tex]2(x+y)[/tex]
[tex]2(x+y)=50[/tex]
[tex]x+y=50/2[/tex]
[tex]x+y=25[/tex]
If y=2 dm
x=25-2=23 dm
If y=4 dm
x=25-4=21 dm
If y=6 dm
x=25-6=19 dm
If y=8 dm
x=25-8=17 dm
If y=10 dm
x=25-10=15 dm
If y=12 dm
x=25-12=13 dm
If y=14 dm
x=25-14=11 dm
x<y
It is not possible
Then, possible combinations are 6
Length width
23 dm 2m
21 dm 4 dm
19 dm 6 dm
17 dm 8 dm
15 dm 10 dm
13 dm 12 dm
How many of 320 million Americans would you predict wear contact lens
Answer:
I think 40 - 60 Million Americans would wear contact lenses.
Think of a two-digit number. What is the probability that it has different digits?
Answer:
9/10
Step-by-step explanation:
The first two digit number is 10 and the last is 99. That's a total of 99-10+1 numbers in all. That simplifies to 90. (Just like if we wanted to see how many numbers was 3,4,5, we would do 5-3+1=3 to get the total number.
Anyways, let's consider first how many 2 digjt numbers whose digits are equal. You have 11 22,33,44 55,66,77,88,99 which is 9 numbers total.
So the amount of 2 digits number whose digits differ is 90-9=81.
The probability that a 2 digit number have different digits is 81/90.
This can reduce. Divide top and bottom by 9 giving 9/10.
Determine the area of the given parallelogram with length 11 and altitude five
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Answer:
55 square units
Step-by-step explanation:
The area of a parallelogram is the product of base length and height:
A = bh
A = (11)(5) = 55 . . . area of the given parallelogram in square units
when solving inequalities,name 2 steps that are the same as solving equations and one difference
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Explanation:
same:
the addition property of equalitythe multiplication property of equality (for positive multipliers)different:
the multiplication property of equality for negative multipliers_____
Additional comment
Multiplication by a negative number has the effect of re-ordering numbers:
-1 < 2 . . . 1 > -2 (both sides multiplied by -1)
Other functions can have the same effect, so care must be taken when applying functions to both sides of an inequality.
1/2 > 1/3 . . . 2 < 3 (reciprocal function applied to both sides)
30° < 60° . . . cos(30°) > cos(60°) (cosine function applied to both sides)
michael has an average of 68% in his 3 papers but that is below the pass mark of 70%. what must be his least score in the fouth paper to enable him pass?
Answer:
72%
Step-by-step explanation:
68% + x/2 = 70%
68 + x = 140
x = 72
Use the definition of a Taylor series to find the first four nonzero terms of the series for f(x) centered at the given value of a. (Enter your answers as a comma-separated list.)
f(x) = 7/1+x a=2
If f(x) = 7/(1 + x), then
f (2) = 7/3
f '(x) = -7/(x + 1)² ==> f ' (2) = -7/9
f ''(x) = 14/(x + 1)³ ==> f '' (2) = 14/27
f '''(x) = -42/(x + 1)⁴ ==> f ''' (2) = -14/27
Then the Taylor series of f(x) about a = 2 is
7/3 + 1/1! (-7/9) (x - 2) + 1/2! (14/27) (x - 2)² + 1/3! (-14/27) (x - 2)³
= 7/3 - 7/9 (x - 2) + 7/27 (x - 2)² - 7/81 (x - 2)³
if( x) means 10 what's (x) divide my 2
Answer:
If you meant that the value of (x) is equal to 10, and you want that value divided by 2, then that would be easy!
10/2 is equal to 5.
If you meant something else, please let me know! :)
what is x divided by one
Answer:
[tex] x \div 1[/tex]
[tex] = x[/tex]
Answer:
[tex]x\div 1=x[/tex]
Step-by-step explanation:
When x is divided by one it is called reciprocal.
reciprocal is the inverse of a number or a value.
examples: The reciprocal of 3 is 1/3, and the reciprocal of 5 is 1/3.
OAmalOHopeO
round 3/5 to 3 decimal points
Answer:
3/5=0.600
Step-by-step explanation:
I hope this answer helps
The answer is 0.6.
Upto 3 decimal places it is 0.600.
Suppose you deposit $500 in a savings account where the interest earned is compounded
continuously at a rate of 10%. How many years will it take the balance in the account to reach
$8000 (round your answer to the nearest year)?
The population of a strain of bacteria doubles in a culture. At noon there were 80 bacteria present and by 4:00 PM there were 20 480 bacteria. Determine algebraically the doubling period. Hint: You DO NOT need to use systematic trials.
Answer:
t = 1/2 hour
Step-by-step explanation:
20480 = 80[tex]x^{t }[/tex]
20480 = 80[tex]x^{4 }[/tex]
20480/80 = [tex]x^{4 }[/tex]
256 = [tex]x^{4 }[/tex]
x = 4
doubling period
2 = [tex]4^{t}[/tex]
t = 1/2 hour
d) A product contains three lasers, and the product fails if any of the lasers fails. Assume the lasers fail independently. What should the mean life equal for 99% of the products to exceed 10000 hours before failure
Solution :
Let the probability laser works = p
The probability that the system works = [tex]$P(\text{all three component works}) = p^3 $[/tex]
= 0.99
Therefore, p = 0.9967
Now for the above probability critical z = -2.72
Hence, the mean life is equal to = [tex]10,000 + 2.72 \times 600[/tex]
= [tex]10,000+1632[/tex]
[tex]=11,632[/tex]
A certain prescription drug diminishes in the system at a rate of 25% per hour. If a person was administered 1450mg of the drug, how much will remain in 4 hours? How many hours will it take for the amount of the drug in their system to be less than 5mg?
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Answer:
459 mgabout 20 hoursStep-by-step explanation:
The decay factor is 1 -25% = 0.75 per hour, so the exponential equation can be written ...
r(t) = 1450·0.75^t . . . . . milligrams remaining after t hours
__
a) After 4 hours, the amount remaining is ...
r(4) = 1450·0.75^4 ≈ 458.79 . . . mg
About 459 mg will remain after 4 hours.
__
b) To find the time it takes before the amount remaining is less than 5 mg, we need to solve ...
r(t) < 5
1450·0.75^t < 5 . . . . use the function definition
0.75^t < 5/1450 . . . . divide by 1450
t·log(0.75) < log(1/290) . . . . . take logarithms (reduce fraction)
t > log(1/290)/log(0.75) . . . . . divide by the (negative) coefficient of t
t > 19.708
It will take about 20 hours for the amount of the drug remaining to be less than 5 mg.
AVX Home Entertainment Inc recently began a "no-hassles" return policy. A sample of 505 customers who recently returned items showed 320 thought the policy was fair, 150 thought it took too long to complete the transaction, and the rest had no opinion. On the basis of this information, make an inference about customer reaction to the new policy. (Round your answers to 1 decimal place.)
Customer reaction Percent
Fair %
Too long %
No opinion %
Answer:
[tex]Fair = 63.4\%[/tex]
[tex]Too\ Long = 29.7\%[/tex]
[tex]No\ Opinion =6.9\%[/tex]
Step-by-step explanation:
Given
[tex]Total=505[/tex] --- customers
[tex]Fair = 320[/tex]
[tex]Too\ Long = 150[/tex]
Required
Complete the table
To complete the table, we simply divide each value by the total number of customers.
So, we have:
[tex]Fair = 320[/tex]
[tex]Fair = \frac{320}{505}[/tex]
[tex]Fair = 0.634[/tex]
Express as percentage
[tex]Fair = 0.634*100\%[/tex]
[tex]Fair = 63.4\%[/tex]
[tex]Too\ Long = 150[/tex]
[tex]Too\ Long = \frac{150}{505}[/tex]
[tex]Too\ Long = 0.297[/tex]
Express as percentage
[tex]Too\ Long = 0.297*100\%[/tex]
[tex]Too\ Long = 29.7\%[/tex]
For the last set, the percentage is calculated using:
[tex]No\ Opinion + Fair + Too\ Long = 100\%[/tex]
So, we have:
[tex]No\ Opinion + 63.4\% + 29.7\% = 100\%[/tex]
[tex]No\ Opinion + 93.1\% = 100\%[/tex]
Collect like terms
[tex]No\ Opinion =- 93.1\% + 100\%[/tex]
[tex]No\ Opinion =6.9\%[/tex]
Please help out really need it !!
Answer:
use the area formula
Step-by-step explanation:
Answer:
rounded to the nearest tenth i think its 40
Ann, Bob, Carol, and Denis own a candy store. After a large argument, they decide to dissolve their partnership using the sealed bid method. Ann bids $320,000 for the store, Bob bids $440,000 for it, Carol bids $240,000 for it, and Denis bids $400,000 for it.
Required:
a. What is Bob's fair share?
b. What is Carol's fair share?
c. What is Denis's fair share?
Answer:
Following are the solution to the given points:
Step-by-step explanation:
[tex]Ann=\$3,20,000\\\\Bob=\$4,40,000\\\\Carol=\$240,000\\\\Denis= \$4,00,000\\\\[/tex]
Each player's offer divided by the total number of players calculates the fair share
Ann's fair share [tex]= \frac{\$320,000}{4} = \$80,000\\\\[/tex]
Bob's fair share[tex]= \frac{\$440,000}{4} = \$110,000\\\\[/tex]
Carol's fair share [tex]= \frac{\$240,000}{4} = \$60,000\\\\[/tex]
Denis's fair share [tex]= \frac{\$400,000}{4} = \$100,000\\\\[/tex]
Because Bob has the highest bid, that receives in the business.
Payments:
Ann [tex]\$80,000[/tex] paid by estate
Bob [tex]= \$440,000 - \$110,000 = \$330,000[/tex] owes estate
Carol [tex]= \$60,000[/tex] paid by estate
Denis [tex]= \$100,000[/tex] paid by estate
Surplus [tex]= \$330,000 - (\$80,000+\$60,000+ \$100,000) = \$90,000[/tex]
Splitting the equally among the four players. therefore one of the each receives:
[tex]\frac{\$90,000}{4}= \$22,500[/tex]
The final settlement of the Ann receives:
[tex]= \$80,000+ \$22,500 = \$102,500[/tex]
given f(x)=2x-4 and g(x)=x213, determine gf[x]]
Step-by-step explanation:
you have to substitute the function g(x) where there's x in the function f(x)
gf(x)=2(x213)-4
if that's x two thirteen then you can multiply the 2 outside the brackets by it
giving you a final answer of
gf(x)=426x-4
hope it helps and sorry if am wrong
Find the measure of the missing angles. WILL GIVE BRAINLIEST
Helpekksdjfkfodldkdkdodidididisj Help
Answer:
The answers to your questions are given below.
Step-by-step explanation:
1. m∠1 and m∠2 are complementary. This statement was given from the question.
2. m∠1 + m∠2 = 90°. Complementary angles add up to give 90°.
3. m∠2 = 74°. This was given in the question.
4. m∠1 + 74 = 90°. Since m∠1 and m∠2 are complementary. Their sum will add up to give 90°
5. m∠1 = 16°
We can prove m∠1 = 16° as shown below:
m∠1 + m∠2 = 90° (complementary angles)
m∠2 = 74°
m∠1 + 74 = 90°
Collect like terms
m∠1 = 90 – 74
m∠1 = 16°
Question 4 please provide explanation for question
Answer:
A
Step-by-step explanation:
We need to find a equation that is where the domain is all real numbers and the range is all real numbers greater than -3
A square root function cannot equal to all real numbers because we cant take the square root of a negative number. so B and C are already wrong.A cubic function range is all real numbers. so y can be greater than -3 but it would also include. values lesser than -3. so D is Wrong.A is right, the domain of a absolute value function is all real numbers. The range of a absolute value is all numbers greater than or equal to zero but if we subtract 3, it changes into all real numbers greater than or equal to -3
Find the area of a rectangle that measures 12ft by 3 1/3 ft
Answer:
40 ft^2
Step-by-step explanation:
The area of a rectangle is given by
A = l*w
=12 * 3 1/3
Change to an improper fraction
= 12 ( 3*3+1)/3
= 12 (10/3)
40
Answer:
[tex]40 {ft}^{2} [/tex]
Step-by-step explanation:
[tex]area = l \times b \\ = 12 \times 3 \frac{1}{3} \\ = 12 \times \frac{10}{3} \\ = \frac{120}{3} \\ = 40 {ft}^{2} [/tex]
Find the length of BC
A. 6.81
B. 7.64
C. 13.37
D. 29.44
Answer:
13.37 = BC
Step-by-step explanation:
Since this is a right triangle, we can use trig functions
cos theta = opp / hyp
cos 27 = BC / 15
15 cos 27 = BC
13.36509 = BC
Rounding to the nearest hundredth
13.37 = BC
An item is regularly priced at$15.It is now priced at a discount of55%off the regular price
Answer:
$6.75
Step-by-step explanation:
The regular price is $15 dollars. The discount is 55% off the $15.
15 * 0.55 = 8.25
15 - 8.25 = 6.75
Hope this helps.
Answer:
discount =8.25
New price 6.75
Step-by-step explanation:
15 is the regular price
The discount is 55%
15*.55
8.25
The new price is the regular price minus the discount
15-8.25
6.75
Which inequality is shown in the graph?
I need help plz
Answer:
I am pretty sure it is B.
Step-by-step explanation:
This is a line with a positive slope, therefore we can discard c and d.
the sign < will mean that the shaded in area will be on your right side.
Rewrite the function f(x)=16^x in four different ways, using a different base in each case.
Answer:
X=1
f(x)=16^1
=16
X=2
f(x)=16^2
256
X=3
f(x)=16^3
=4096
X=4
f(x)=16^4
=65536
Here are four different ways to rewrite the function f(x) = 16^x, using a different base for each case:
Using base 2:
f(x) = (2^4)^x = 2^(4x)
Using base 3:
f(x) = (3^2)^x = 3^(2x)
Using base 10:
f(x) = (10^(log10(16)))^x = 10^(log10(16) * x)
Using base e (natural logarithm):
f(x) = (e^(ln(16)))^x = e^(ln(16) * x)
How to explain the functionIn these rewritten forms, the exponentiation of the base is expressed as a simpler expression.
This involves the new base, which helps to illustrate the relationship between the original function and the different bases used.
Learn more about functions
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Salma invested $8000 in a fund for 6 years and was paid simple interest. The total interest that she received on the investment was $1400. As a percentage, what was the annual interest rate of her investment?
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Answer:
about 2.917%
Step-by-step explanation:
The simple interest formula can be used. Fill in the known values and solve for the unknown.
I = Prt . . . . principal P invested at rate r for t years
1400 = 8000(r)(6)
r = 1400/48000 = 7/240 = 0.0291666...
Salma's interest rate was about 2.917% per year.
Which function has a range of y < 3?
y - 3(2)
y = 2(3)
O y=-(2)x+ 3
Oy- (2) * - 3
Given:
The range of a function is [tex]y<3[/tex].
To find:
The function for the given range from the given options.
Solution:
In option A, the given function is:
[tex]y=3(2)^x[/tex]
Here, [tex](2)^x[/tex] is always greater than 0. So, [tex]3(2)^x[/tex] is also greater than 0, i.e., [tex]y>0[/tex].
In option B, the given function is:
[tex]y=2(3)^x[/tex]
Here, [tex](3)^x[/tex] is always greater than 0. So, [tex]2(3)^x[/tex] is also greater than 0, i.e., [tex]y>0[/tex].
In option C, the given function is:
[tex]y=-(2)^x+3[/tex]
Here,
[tex](2)^x>0[/tex]
[tex]-(2)^x<0[/tex]
[tex]-(2)^x+3<0+3[/tex]
[tex]y<3[/tex]
The range of this function is [tex]y<3[/tex]. So, option C is correct.
In option D, the given function is:
[tex]y=(2)^x-3[/tex]
Here,
[tex](2)^x>0[/tex]
[tex](2)^x-3<0-3[/tex]
[tex]y<-3[/tex]
The range of this function is [tex]y<-3[/tex]
Therefore, the correct option is only C.
