If 16g if a radioactive substance are present initially and 5yr later only 8g remain how much substance will be present after 9yr
9514 1404 393
Answer:
4.59 g
Step-by-step explanation:
The half-life is given as 5 years, so the amount remaining after 9 years will be ...
remaining = initial × (1/2)^(t/(half-life))
remaining = (16 g)×(1/2)^(9/5) ≈ 4.59 g
About 4.59 g of the substance will remain after 9 years.
I need an equation for this algebra problem
Answer:
2.5 hours
Step-by-step explanation:
Given
The information in the attachment
To solve this question, first we calculate the slope
[tex](t_1,B_1) = (1,19,5\%)[/tex]
[tex](t_2,B_2) = (2,13\%)[/tex]
The slope is:
[tex]m = \frac{B_2 - B_1}{t_2 - t_1}[/tex]
[tex]m = \frac{13\% - 19.5\%}{2-1}[/tex]
[tex]m = \frac{-0.065}{1}[/tex]
[tex]m = -0.065}[/tex]
The equation is calculated as:
[tex]B - b_3 = m(t - t_3)[/tex]
Where
[tex]m = -0.065}[/tex]
[tex](t_3,B_3) = (3,6.5\%)[/tex]
This gives
[tex]B - 6.5\% = -0.065(t - 3)[/tex]
[tex]B - 6.5\% = -0.065t +0.195[/tex]
[tex]B -0.065 = -0.065t +0.195[/tex]
[tex]B = -0.065t +0.195 +0.065[/tex]
[tex]B = -0.065t +0.26[/tex]
To calculate the time at 9.75%.
We take B = 9.75%
So, we have:
[tex]9.75\% = -0.065t +0.26[/tex]
Solve for t
[tex]0.0975= -0.065t +0.26[/tex]
Collect Like Terms
[tex]0.065t= -0.0975 +0.26[/tex]
[tex]0.065t= 01625[/tex]
[tex]t = 0.1625/0.065[/tex]
[tex]t = 2.5[/tex]
Hence, it will take 2.5 hours.
Solve the math problems
X - 1 = 12; X = ?
X + 5 = 12; X = ?
X - 5 = 55. X = ?
X + 9 = 80: X = ?
X-2 = 40: X = ?
X + 2 = 31; X = ?
X-6 = 27: X = ?
X - 10 = 56; X = ?
X + 1 = 70; X = ?
X + 9 = 31; X = ?
Answer:
13, 7, 60, 71, 42, 29, 21, 66, 69, 22.
Step-by-step explanation:
Hope it's helpful
Find the measure of the arc.
Answer: 90
Step-by-step explanation:
The Ferris wheel is the most popular ride. In 1 hour, the Ferris wheel had 240 riders. If that was 60% of the total number of riders, then how many riders did the Ferris wheel have?!!PLEASE ANSWER!!
Answer:
400 riders
Step-by-step explanation:
The Ferris wheel had 400 riders.
400*0.60=240.
Answer:
Y = 144
Step-by-step explanation:
60 times = 14400
14400 = y times 100
Find the length of the third side to the nearest tenth.
8
5
Answer:
The length of third side is: 6.3
Step-by-step explanation:
Given triangle is a right triangle where
Base = ?
Perpendicular = 5
Hypotenuse = 8
Let x be the base
As it is a right-angled triangle, Pythagoras theorem can be used to find the third side
[tex]Hypotenuse^2 = Base^2 + Perpendicular^2[/tex]
Putting the known values
[tex](8)^2 = x^2 + (5)^2\\x^2 = (8)^2-(5)^2\\x^2 = 64-25\\x^2 = 39\\[/tex]
Taking square root on both sides
[tex]\sqrt{x^2} = \sqrt{39}\\x = 6.24499[/tex]
Rounding off to the nearest 10th
Base = 6.3
Hence,
The length of third side is: 6.3
ASAP please help me I need this quick
The question and answers are in the picture
Answer:
25
Step-by-step explanation:
maybe this will help you
Answer:
C. 125 cm^3
Step-by-step explanation:
Hope this helps!! Brainliest please :)
You are downloading songs to your MP3 player. The ratio of pop songs to rock songs is 5 : 4. You download 40 pop songs. How many rock songs do you download?
You download ___
rock songs.
Answer:
You download 32 rock songs.
Step-by-step explanation:
*im a 7th grader so dont trust me with this answer lol*
The ratio 5 : 4 can also be written as the fraction 5/4.
The ratio pop songs, 40 : rock songs, r can be written as the fraction 40/r
Set an equation:
40/r = 5/4
Cross Multiply:
5r = 160
Divide 5 from both sides:
r = 32
There you have it, the amount of rock songs downloaded! Hopefully this helps!
y=4x+1
y=-3/4 |x|
how do i graph these equations (separate problems)?
3.) Jimena used her calculator to divide 2 by 13.
The calculator screen shows the number: 0.1538461.
Round Jimena's answer to the nearest tenth. =
Answer: 0.2
Step-by-step explanation:
Find the value of the power 6 to the -4th
Answer:
6 to the -4th is 7.716 x 10^-4
Step-by-step explanation:
marissa can read 15 pages in 5 minutes and 30 seconds how long will it take for her to read 105 pages
Answer:
38.5 minutes
Step-by-step explanation:
105 divided by 15=7
7 x 5 minutes and 30 seconds is 38.5 minutes
The distance between(-12,-9) and (12,-9)
Answer:
24 units
Step-by-step explanation:
12 to 0
12 to 12
Answer:
30
brainliest??
Step-by-step explanation:
Identify the pattern rule for this sequence
Answer:
it should be c
Step-by-step explanation:
A rectangular photograph is reduced to 75% of its original size. The photo was originally 12 inches by 16 inches. What is the perimeter, in inches, of the reduced picture?
y=-3x2 + 18x + 10?
What is the axis of symmetry
Answer:
x = 3
Step-by-step explanation:
The formula for the axis of symmetry is x = -b/[2a]. Here, a = -3 and b = 18.
-18
Thus, the axis of symmetry is x = - ------------ = 3, or x = 3
2[-3]
A random sample of 500 people is taken. 260 of them rent (as oppose to own) their residence. Compute a 95% confidence interval for the true proportion
Answer: A 95% confidence interval for the true proportion (p) will be (0.4762136, 0.5637864).
Step-by-step explanation:
Let p = True proportion of people rent their residence.
Given: n= 500
People rent their residence = 260
[tex]p=\dfrac{260}{500}=0.52[/tex]
z-value for 95% confidence level = 1.96
A 95% confidence interval for the true proportion will be :
[tex]p\pm z^*\sqrt{\dfrac{p(1-p)}{n}}[/tex]
[tex]0.52\pm (1.96)\sqrt{\dfrac{0.52(1-0.52)}{500}}\\\\=0.52\pm(1.96\sqrt{\dfrac{0.2496}{500}})\\\\=0.52\pm 1.96\sqrt{0.0004992}\\\\=0.52\pm (1.96)(0.02234)\\\\=0.52\pm0.0437864\\\\=(0.52-0.0437864,\ 0.52+0.0437864)\\\\=(0.4762136,\ 0.5637864)[/tex]
A 95% confidence interval for the true proportion (p) will be (0.4762136, 0.5637864).
PPPPPPPLLLLLLLLLLLLLLEEEEEEEEEESSSSSSS HELP ME
Mark bought 5 t-shirts for $32.35. What was the mean cost of one shirt?
Answer:
6.47 i THINK . or just use a search engine .
Step-by-step explanation:
i just divided 32.35 by 5
Answer:
6.47 thank me
Step-by-step explanation:
(1 point) A pond contains 100 fish, of which 40 are carp. If 20 fish are caught from the lake, what are the mean and variance of the number of carp among those 20
Answer:
E(X) = 6
Var(X) = 3.394
Step-by-step explanation:
Let X represent the number of carp caught out of the 20 fishes caught. Now, if we are to assume that each
of the (100, 20) ways to catch the 20 fishes will be equally likely.
Thus, we can say that X fulfills a hypergeometric
distribution with parameters as follows;
n = 20, N = 100, k = 30
Formula for expected mean value in hypergeometric distribution is;
E(X) = nk/N
E(X) = (20 × 30)/100
E(X) = 6
Formula for variance is;
Var(X) = (nk/N) × [((n - 1)(k - 1)/(N-1))) + (1 - nk/N)]
Var(X) = ((20 × 30)/100) × [((20 - 1)(30 - 1)/(100 - 1)) + (1 - (20 × 30/100)]
Var(X) = 6 × 0.5657
Var(X) = 3.394
Solve the system by substitution. y = 8x + 32 Y= -8x
If Aaron tunes into his favorite radio station at a randomly selected time, there is a 0.20 probability that a commercial will be playing.
Interpret this probability as a long-run relative frequency.
Answer:
This simply means that, on a scale of 1 - 100, there is a 20 percent chances that, when Aaron tunes into the radio frequencies in search of a station, he will be able to get one station playing a commercial at that particular time.
For example, at 11:00am each day, him tuning into his favorite radio station would be 20 percent possible to meet one playing a commercial.
Step-by-step explanation:
Using the concept of relative frequency, the interpretation is that over a large number of days, in around 20% of the times he tunes is his favorite station a commercial will be playing.
A probability of an outcome A of a% means that over a large number of experiments, the relative frequency(which is the number of desired outcomes divided by the number of total outcomes) of event A will be of [tex]\frac{a}{100}[/tex].In this problem, there is a 0.2 probability of a commercial playing when he tunes in his favorite station.Hence, the interpretation is that over a large number of days, in around 20% of the times he tunes is his favorite station a commercial will be playing.A similar problem is given at https://brainly.com/question/16967884
Solute x/3=5 do this question step vise
Answer:
x=15
Step-by-step explanation:
3*5=15
15/5=3
Answer:
x = 15
Step-by-step explanation:
x/3 = 5
3* x/3 = 3*5
x=15
Do the ratios 3/20 and 1/4 form a proportion?
Answer:
yes
Step-by-step explanation:
if the denomentators are dividable, than it is a equivalent equation
what is 25+25458752452+5454466125+545454885422574212=
Answer:
5.4545492e+17
Step-by-step explanation:
aka a really big number
Pran ran 29 miles less than Robin last week. Pran ran 19 miles. How many
miles did Robin run?
Write an inequality for the following 2 STATEMENTS. You
do NOT need to solve them.
1)two less than a number is less than 9
2)the sum of a number and 8 is more than 4
Answer:
We
Given below are pictures of some common reptiles. Unscrambles
land and water.
jumbled letters and write their names:
an
P
1.
2.
Snake
TLALIGAOR
3.
KNSAE
4.
TRUTLE
Step-by-step explanation:
Need help with this math problem ASAP. Look at the picture attached. The linear function f(x) passes through the points (0,3) and (2,7). A few values from the exponential function g(x) are shown in the table. What is the positive difference in the y-intercept value of f(x) and g(x)?
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[tex]f(x) = 2x + 3[/tex]
And
[tex]g(x) = 2 \times {3}^{x} \\ [/tex]
_________________________________
To find the y-intercept of any equation just need to put 0 (( zero )) instead of the x in the equation...
Let's do it...._________________________________
In f ( x ) :
[tex]y - intercept = f(0)[/tex]
[tex]f(x) = 2x + 3[/tex]
[tex]f(0) = 2(0) + 3[/tex]
[tex]f(0) = 3[/tex]
Thus :
[tex]y - intercept = 3[/tex]
##############################
In g ( x ) :
[tex]y - intercept = g(0)[/tex]
[tex]g(x) = 2 \times {3}^{x} [/tex]
[tex]g(0) = 2 \times {3}^{0} [/tex]
[tex]g(0) = 2 \times 1[/tex]
[tex]g(0) = 2[/tex]
Thus :
[tex]y - intercept = 2[/tex]
_________________________________
The positive difference in the y-intercept value of f ( x ) and g ( x ) is :
[tex] |3 - 2| = |1| = 1[/tex]
So write this in the box : 1
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And we're done....
♥️♥️♥️♥️♥️♥️♥️♥️♥️♥️♥️♥️♥️♥️
Given a point and slope, find the equation. (1, 4.8) and m=3.7
y=mx+b the m=3.7 What is b??
bro pls help me lol idk what i'm doing
Answer:
60 would be a good inverse for this table, it is best for xy, 60 is the k/p in this equation.
Step-by-step explanation:
Answer:
1.5
Step-by-step explanation:
The formula for inverse variation is xy=k. So i did 3*5 which is 15 and then I did 15*1 which is 15 and 30*0.5 which is 15. So know i know that 10 times something has to equal 15 so i do 15/10 to get 1.5 which is my answer
A map of California has a scale factor of 1 inch = 16 miles. The distance on the map from Riverside to Chula Vista is 3.5 inches. How far are the two cities in real life?
Answer:
56 miles
Step-by-step explanation: