a radioactive substance has a half-life of 2 seconds. A scientist begins with a sample of 20 grams. How much of the substance remains after 8 seconds?
Answer:
1.25 g
Step-by-step explanation:
you start with 20g at 0 seconds.
divide by half after 2 seconds and you have 10g.
at 4 seconds you have 5g.
at 6 seconds you have 2.5g.
at 8 seconds you have 1.25g.
The size of the substance after 8 seconds will be 1.25 g
What is an expression?The mathematical expression combines numerical variables and operations denoted by addition, subtraction, multiplication, and division signs.
Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also denote the logical syntax's operation order and other properties.
Given that a radioactive substance has a half-life of 2 seconds. A scientist begins with a sample of 20 grams.
Start with 20g at 0 seconds and divide by half after 2 seconds and you have 10g.
4 seconds you have 5g.
6 seconds you have 2.5g.
8 seconds you have 1.25g.
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Which of the following best describes the graph shown below?
Answer: D
Step-by-step explanation:
The Sydney Harbour Bridge is approximately 1200 metres long. A model of the bridge is built with a scale of 1:6000. What is the length of the model?
Pick one:
5cm
20cm
200cm
720cm
Answer:
20cmStep-by-step explanation:
The Sydney Harbour Bridge is approximately 1200 metres long. A model of the bridge is built with a scale of 1:6000. What is the length of the model?
Pick one:
5cm
20cm
200cm
720cm
--------------------
scale = 1:6000
so
1200 : 6000 = 0.2m
0.2m = 20 cm
Answer:
20cm
Step-by-step explanation:
«A scale of 1:6000» means the model is smaller than the bridge by a factor of 6000. We can also make up a proportion [tex]\dfrac{1}{6000}=\dfrac{x}{1200}[/tex], where the left side is the scale, x is the model length, 1200 is the bridge length (in meters). So, finding x or just dividing 1200 by 6000, we get 0.2 meters. Provided 1 m = 100 cm, 0.2 m is 0.2 × 100 = 20 cm.
If the parallel sides of a trapezium are 2 cm apart and their sum is 10 cm then find its area.
Answer:
[tex] {10cm}^{2} [/tex]Step-by-step explanation:
Given,
Sum of parallel sides of the trapezium = 10 cm
Distance between or Height of the trapezium = 2 cm
As we know,
Area of a trapezium
[tex] = \frac{1}{2} \times (sum \: of \: parallel \: sides) \times height[/tex]
Therefore,
Area of the given trapezium will be,
[tex] = \frac{1}{2} \times 10 \: cm \times 2 \: cm[/tex]
(On Simplification )= 1 × 10 cm × 1 cm
(On multiplying)[tex] = 10 {cm}^{2} [/tex]
Hence,
The Area of the trapezium is 10 sq.cm (Ans)
Given :
The parallel sides of a trapezium are 2 cm apart and their sum is 10 cm.To Find :
Its area.Solution :
We know that,
[tex]{ \qquad \: \pmb{ \dfrac{1}{2} \times (sum \: of \: the \: parallel \: sides) \times height} = \pmb{Area_{(trapezium)}}}[/tex]
Now, Substituting the given values in the formula :
[tex]\qquad { \dashrightarrow \: { \sf{ \dfrac{1}{2} \times 10\: \times 2 \: = {Area_{(trapezium)}}}}}[/tex]
[tex]\qquad { \dashrightarrow \: { \sf{ \dfrac{1}{2} \times 20 = {Area_{(trapezium)}}}}}[/tex]
[tex]\qquad { \dashrightarrow \: { \sf{ \dfrac{20}{2} = {Area_{(trapezium)}}}}}[/tex]
[tex]\qquad { \dashrightarrow \: { \sf{ 10 = {Area_{(trapezium)}}}}}[/tex]
⠀
Hence,
The area of the trapezium = 10 cm² .Look at pic! It isnt A!
Please help me with this homework
√54/3, √13, 6, 8, 26/3
6x - y^2 + 3z ;if x = 4,y = 7,z = 10
work out 4 1/2 - 1 1/3
Answer:
3 1/6
brainliest?
2x2-5x-2 solve by quadratic formula 9leave answers in simplest radical form)
Answer:
-5x+2
Step-by-step explanation:
1. Multiply number 2 and 2=4 so it is
4-5x-2
2. Combine like terms
-5x+4-2
3. Subtract the numbers
-5x+2
can someone help me 6 is 1.2 percent of what number
500
Step-by-step explanation:
I'm not really sure but I hope it helps
2m to 2km converted representative fraction
Answer:
1/1000
Step-by-step explanation:
How many months would it take the bamboo plant shown in the graph to be 66 inches tall
Answer:
18 months
Step-by-step explanation:
c
Monique wants to check out as many books by her favorite author as possible. She can check out 3 books at a time from her library, where there are 6 books available written by her favorite author. How many different sets of 3 of these books can Monique choose
Monique can choose 20 different sets of 3 of the books
What is a combination?The set of books she can select from the library is an illustration of combination (or selection)
The expression that represents combination is represented as:
[tex]^nC_r = \frac{n!}{(n - r)!r!}[/tex]
Where:
The total number of books [tex]n = 6[/tex]The set of books to check out [tex]r = 3[/tex]So, we have:
[tex]^6C_3 = \frac{6!}{(6 - 3)!3!}[/tex]
Evaluate the differences
[tex]^6C_3 = \frac{6!}{3!3!}[/tex]
Evaluate the factorials
[tex]^6C_3 = \frac{720}{6 \times 6}[/tex]
Evaluate the products
[tex]^6C_3 = \frac{720}{36}[/tex]
Divide 720 by 36
[tex]^6C_3 = 20[/tex]
Hence, Monique can choose 20 different sets of 3 of the books
Read more about combination at:
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Answer:
it is in fact 20 (for khan)
Step-by-step explanation:
credit goes to person above
If m20 = 4x - 20, and m2Q = 3x + 5, what is mo?
P
M
♡
♡
R
mzo =
Answer:
hello hhhhh
Step-by-step explanation:
Answer:
direct message me I will help u out
What is the 4th equivalent fraction to 1/12?
Answer:
Where's the Answer? There's No
Hello there!
Remember that equivalent fractions have the same value.
[tex]\frac{1}{2} , \frac{2}{24} ,\frac{3}{36}, \frac{4}{48}[/tex]
Therefore, the 4th equivalent fraction to 1/12 is [tex]\frac{4}{48}[/tex]Hope this helps you!
~Just a felicitous girlie
#HaveASplendidDay
[tex]SilentNature :)[/tex]
Is 126 divisible by 3
Answer:
yes
Step-by-step explanation:
Answer:
Yes
Step-by-step explanation:
126/3 = 42
At what coordinate point with the graph of y = 3x - 8 intersect that of its inverse?
Answer:
Point of Intersection: (-4, -4)
Step-by-step explanation:
Given the linear equation, y = 3x + 8:
We must determine its inverse, which will enable us to find the point of intersection between the given equation and its inverse.
Start by switching x and y in the given linear equation:
y = 3x + 8
x = 3y + 8
Next, subtract 8 from both sides:
x - 8 = 3y + 8 - 8
x - 8 = 3y
Multiply both sides with ⅓ to isolate y:
⅓ (x - 8) = (3y) ⅓
[tex]\displaytext\mathsf{\frac{1}{3}x\:-\frac{8}{3}\:=\:y}[/tex]
Replace y with [tex]\large{\textit{f}\:^{-1}(\textit{x}\:)}[/tex]:
[tex]\displaytext\mathsf{\textit{f}\:^{-1}(\textit{x}\:)\:=\frac{1}{3}x\:-\frac{8}{3}}[/tex] ⇒ This is the inverse function of y = 3x + 8.
Graph both equations:Next, we must graph both equations.
Plot the y-intercept, (0, 8), and use the slope of the given linear equation, m = 3, to plot other points on the graph.
Similarly, to graph the inverse function, take the y-intercept, [tex]\displaytext\sf{(0,\:-\frac{8}{3})}[/tex], and use the slope, m = ⅓, to plot other points on the graph.
Attached is the graph of the linear equation, y = 3x + 8, and its inverse, [tex]\displaytext\mathsf{\textit{f}\:^{-1}(\textit{x}\:)\:=\frac{1}{3}x\:-\frac{8}{3}}[/tex] , where it shows that the point of intersection occurs at point, (-4, -4).
find the value of:
64 x (1/4)³
A. 1
B. 4
C. 15
D.64
brainliest if correct!!
Answer:
The answer is A. 1
you're welcome
what is the answers to 10% of 50 i multiply 10 x 50
NO!!!!!!!!!!
10% of 50 is 50/100x10 0r simply 50/10, so the answer is 5
Answer:
5
Step-by-step explanation:
10%×50=10/100×50
=5
Three partners are investing a total of $900,000 to open a garden and landscaping store. Their investments are in the ratio of 2:3:5. .
Which of the following tables does not represent a function?
x y
-1 1
-2 1
-3 1
x y
-5 1
-5 -2
-5 -5
x y
-4 0
2 0
5 7
x y
-5 1
-3 -2
-1 -5
Step-by-step explanation:
the second one (with the -5 as x values) is not a function, because the valid x value -5 has more than one associated different solution value y.
for a function a valid x value can lead only to exactly one result y value.
1.) From a group of 8 people, 5 will each win $1,000. How many different winning groups are
possible?
A.) 56
B.) 6720
C.) 168
D.) 336
Anwser 6720 ways different
Step-by-step explanation:
In this case, we must calculate the different ways using the permutation formula:
nPr = n! / (n - r)!
where n is the total number of people and r would come being the group of person that you want to put together the groups, therefore n = 8 and r = 5
replacing:
8P5 = 8! / (8 - 5)!
8P5 = 6720
That is to say that there are 6720 ways different winning groups are possible
if y varies inversely as n and m = 8 when n = 3 find m whenn =12
Answer:
24
Step-by-step explanation:
m=8x4 n=3x4 so that is the answer
150 is 15% of what number
Answer:
1000
Step-by-step explanation:
15 = 15/100 x a
a = 150 ÷ 15/100
a = 150 x 100/15
a = 1000
w + 12 = 20 *
ANSWER ASAP PLS
Answer:
the nwser is 8 please mark brainliest
Step-by-step explanation:
on average, 8 potatoes cost $1.50 at a farmers market. fernando needs to buy 22 potatoes
a. estimate the cost of 22 potatoes. explain
b. how much will it cost fernando to buy 22 potatoes? how does this compare to your estimate ?
c. how many potatoes could fenando buy with $7 ?
d. what is the unit cost per potato
Answer: a) it will cost him $4.13 rounded
B)about 36
C)$ 0.19 (rounded) per potato
2.4x2.4x8.75.8.75 what is the anwser pls
Answer:
0.432 x ^10
Step-by-step explanation:
9. 2 less than 3 times a number is the same as 2114. What is the number?
Enter your answer as a decimal or simplified mixed number in the box. The number is.
Answer:
705.3 repeated I don't know if that's what you want but
3 times of 705.33 and 2 subtracted is equal to 2114.
What is Simplification?Simplification in mathematical terms is a process to convert a long mathematical expression in simple and easy form.
Given that,
2 less than 3 times a number equal to 2114.
Let the required number is x.
According to given condition,
3x - 2 = 2114
3x = 2114 + 2
3x = 2116
x = 2116 / 3
x = 705.33
The required number is 705.33.
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The ratio of two numbers is 7:2. If the greater number is 28, find the smaller one.
Answer:
Answer:
8
Step-by-step explanation:
7 : 2
We know the larger number is 28
28 : x
We multiply 7 * 4 = 28, so multiply the first ratio by 4
7*4 : 2*4
28 : 8
The second number is 8
Please give brainliest
Have a nice day!
100% of will give me 93
Answer:
Hi Wdym m=by 100% of will give me 93
Step-by-step explanation:
