The mass of the substance left after 12 days is 501.51g.
Data;
Half life = 4 daystime = 12 daysNo = 7600Half - LifeThis is defined as the time taken for the radioactive sample to decay to half it's initial size.
This is given as
[tex]T_\frac{1}{2} = \frac{\ln 2}{\lambda}[/tex]
where
λ = disintegration constantLet's substitute the values and find the disintegration constant
[tex]T_\frac{1}{2} = \frac{\ln 2}{\lambda} \\4 = \frac{0.693}{\lambda} \\\\\lambda = \frac{0.693}{4}\\ \lambda = 0.17325[/tex]
But the value of a radioactive substance present at a given time is
[tex]N_t = N_o e^-^\lambda ^t[/tex]
Let's substitute the values and solve.
[tex]N_t = 7600 e^-^0^.^1^7^3^2^*^1^2\\N_t = 7600 * 0.065988\\N_t = 501.509g[/tex]
The mass of the substance left after 12 days is 501.51g.
Learn more on radioactivity here;
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Enola has a toy car collection. She keeps some in a display case and the rest on the wall. 155 of her toy cars are on the wall, and 69% of her toy cars are in the display case. What is the total number of toy cars in Enola's collection?
Give me brainliest if right: 106.95
The total number of toy cars in Enola's collection is 500 if 155 of her toy cars are on the wall, and 69% of her toy cars are in the display case.
What is the percentage?It's the ratio of two integers stated as a fraction of a hundred parts. It is a metric for comparing two sets of data, and it is expressed as a percentage using the percent symbol.
It is given that:
She keeps some in a display case and the rest on the wall. 155 of her toy cars are on the wall, and 69% of her toy cars are in the display case.
Let x be the total number of toy cars in Enola's collection:
69% of x = x - 155
0.69x = x - 155
0.31x = 155
x = 500
Thus, the total number of toy cars in Enola's collection is 500 if 155 of her toy cars are on the wall, and 69% of her toy cars are in the display case.
Learn more about the percentage here:
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87.125 is it rational or irrational? Explain how.
Answer:
87.125 is rational
Step-by-step explanation:
it is a rational number because it can be represented as a fraction
factorise 3-x^2 can’t do it
Answer:
(√3 - x)(√3 + x)
Step-by-step explanation:
Use difference of two square formula:
a² - b² = (a - b)(a + b)
So a² = 3 ⇒ a = √3
and b² = x² ⇒ b = x
Therefore, 3 - x² = (√3 - x)(√3 + x)
50 points pls help!!
Answer:
p = 23
q = 18
Step-by-step explanation:
The four interior angles of a square are all 90° each
4p - 2 = 90
⇒ 4p = 92
⇒ p = 92 ÷ 4
⇒ p = 23
5q = 90
⇒ q = 90 ÷ 5
⇒ q = 18
Answer:
p=23; q=18.
Step-by-step explanation:
1) m∠(XWZ)=90, then 4p-2=90 and p=23°;
2) m∠(WZY)=90, then 5q=90 and q=18°.
Pls answer the question attached.
I WILL MARK U BRAINLIST
Area of figure = area of trapezoid + area of rectangle
A(rectangle) = 18 x 5 = 90 cm2
A(trapezoid) = (10+18) x (13-5) : 2 = 112 cm2
A(figure) = 112 + 90 = 202 cm2
multiply 8/2a^5 • 6/12a^2
Answer:
2/a^7
Step-by-step explanation:
(2)/(3)a-7+(7)/(18)a-5(1)/(6)
Answer:
19a - 141
-------------
18
Step-by-step explanation:
Combine multiplied terms into a single fraction
Combine multiplied terms into a single fraction
Multiply the numbers
help with question pls I don't understand
Answer:
15x^3y+6x^2y^2+9xy^3
Step-by-step explanation:
3xy ( 5x^2 +2xy +3y^2)
Distribute the 3xy to all terms in the parentheses
3xy*5x^2+3xy*2xy+3xy*3y^2
15x^3y+6x^2y^2+9xy^3
Answer:
15[tex]x^{3}[/tex]y + 6[tex]x^{2}[/tex][tex]y^{2}[/tex] + 9x[tex]y^{3}[/tex]
Step-by-step explanation:
multiple everything in the brackets by 3xy
3xy x 5[tex]x^{2}[/tex] = 15[tex]x^{3}[/tex]y
3xy x 2xy = 6[tex]x^{2}[/tex][tex]y^{2}[/tex]
3xy x 3[tex]y^{2}[/tex] = 9x[tex]y^{3}[/tex]
15[tex]x^{3}[/tex]y + 6[tex]x^{2}[/tex][tex]y^{2}[/tex] + 9x[tex]y^{3}[/tex]
A kite flying in the air has an 11-ft line attached to it. Its line pulled taut and casts a 9 -ft shadow. Find the height of the kite. If necessary, round your answer to the nearest tenth.
Step-by-step explanation:
All we have to do is apply the Pythagorean theorem which states that a²+b²=c²
where c is the hypotenuse of the triangle or the side facing the 90° angle.
Moreover a & b are the other two sides of the triangle.
[tex]11 {}^{2} = {9}^{2} + h {}^{2} [/tex]
where h is the height from the ground
[tex]121 = 81 + {h}^{2} [/tex]
[tex]h {}^{2} = 121 - 81[/tex]
[tex]h {}^{2} = 40[/tex]
[tex]h = \sqrt{40} = 6.324[/tex]
Rounding to the nearest tenth,
[tex]h = 6.3[/tex]
I need help on 12 lol
Answer:
68.58m
Step-by-step explanation:
hope it helps!!!
I’m just a bit confuse on 16. Can someone help me T__T
Answer:
40 degrees
Step-by-step explanation:
m<3 = m<4
2x=80
x=40 degrees
Lena pays $8.96 for every 3 ounces of coffee. If she were to
graph the relationship between the number of ounces of
coffee and the total cost, what would be the meaning of the
slope of this graph?
Answer:
A: the cost per pund of coffee
Step-by-step explanation:
You need x and y- values. So one would be the pound (x) and the other would be the cost (y)
Desperately need help
[tex]\begin{cases} x=-5\implies &x+5=0\\ x=3\implies &x-3=0 \end{cases}\qquad \implies \underline{a(x+5)(x-3)~~ = ~~\stackrel{0}{y}} \\\\\\ \stackrel{\textit{we also know that}}{P(0)=-30}\implies \begin{cases} x=0\\ y=-30 \end{cases}\implies a(0+5)(0-3)~~ = ~~-30 \\\\\\ a(5)(-3)=-30\implies -15a=-30\implies a=\cfrac{-30}{-15}\implies \boxed{a=2} \\\\[-0.35em] ~\dotfill\\\\ 2(x+5)(x-3)=y\implies 2(\stackrel{F~O~I~L}{x^2+2x-15})=y\implies \underline{2x^2+4x-30=y}[/tex]
Check the picture below.
PLEASE HELP!
subtract [tex]\frac{3p}{5}[/tex] - [tex]\frac{1}{6}[/tex]
Answer:
Your answer is: 18p-5/30
To subtract fractions, find the LCD and then combine.
Step-by-step explanation:
Hope this helped : )
Answer:
---------------------------------answer will be (18p-5)/30_____________________Sofie claims to be a tasting expert. To test her abilities, someone bakes Sofie a cake using 3 of the following
ingredients:
Coffee
Nutmeg
Vanilla
Cinnamon
Sea salt
Ginger
Sofie's challenge is to identify which set of 3 ingredients was used in the cake. Suppose that Sofie is just
randomly guessing.
What is the probability that Sofie correctly identifies the set of 3 ingredients in the cake?
Summing all the ingredients to get the total sample size, we applied the formula for obtaining the probability which is
Pr(3) = 0.5
ProbabilityGiven Data
Sample Space
CoffeeNutmegVanillaCinnamonSea saltGingerTotal Sample size = 6
Probability of identifying 3 ingredient used is
Pr(3) = 3/6
Pr(3) = 1/2
Hence the Probability is 0.5
Learn more about probability here:
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Answer:
1/20
Step-by-step explanation:
From Kahn
a practice field is 250 feet long . the game field is 40% longer than the practice field . how long is the game field
The game field is 350 40 percent for 250 is 100 and 250 plus 100 is 350
please help its for algebra 1
Answer:
(-1, -6)
Step-by-step explanation:
If you do rise over run you get the same slope as 8x+7y=-50
Eric runs every day. He can run 5 miles in 50
minutes. What is the unit rate that Eric runs in
one minute?
Answer:
10
Step-by-step explanation:
If he runs 50 minutes 50 divided by 5 is 10
what is the fractions that are multiples of 1/6
Answer:
1/31/2those would be the only onesIn the following pictograph, how many total books have the four groups read?
a. 27
b. 90
c. 54
d. 9
Best answer gets brainliest!
Answer:
c; 54
Step-by-step explanation:
to find the answer you can first add all the books together
this can be represented by
3 + 2 + 2.5 + 1.5
this answer is 9
then multiply it by 6
9 * 6 = 54
is is c
isosceles and equilateral
Answer:
I think it is 60°
Step-by-step explanation:
b/c angle of triangle is 180° and when we divide 180° by 3 it will be 60°
A package contains 4 cups of trail mix. He wants to divide the trail mix into 1/3 cup servings. How many 1/3 cup servings are there in 4 cups? Explain how you found your answer.
Answer: 12
Step-by-step explanation:
to find this, divide 4 by 1/3:
4/(1/3) = 4x3 = 12
there are 12 1/3 cup servings in 4 cups
Answer:
Hey there!
Contains 4 cups of trail mix
He wants 1/3 go cup servings
=> 4 ÷ 1/3
=> 4×3/1
=> 12
Therefore, there are 12 of 1/3 in 4 cups
Maddie has 18 flowers plants to put in her garden. she wants to plant them on 3 rows with an equal number on each row. how many rows will she plant
Answer:
6
Step-by-step explanation:
18 ÷ 3 = 6
3+3+3+3+3+3=18
Answer:
6 per row
Step-by-step explanation:
If Maddie has to spread out a total number of flowers (18) over a set number of sections (3) you would be able to solve this by dividing the total into the sections, which would look something like 18/3.
Given that ¹/x=²/y+¹/z. express y interms of x and z. if x=5 and z=10. find the value of y leaving your answer as a mixed fraction
Answer:
[tex]y=\dfrac{2xz}{(z-x)}[/tex]
Step-by-step explanation:
Given:
[tex]\dfrac{1}{x}=\dfrac{2}{y}+\dfrac{1}{z}[/tex]
[tex]\implies \dfrac{2}{y}=\dfrac{1}{x}-\dfrac{1}{z}[/tex]
[tex]\implies \dfrac{2}{y}=\dfrac{z-x}{xz}[/tex]
[tex]\implies 2xz=y(z-x)[/tex]
[tex]\implies y=\dfrac{2xz}{(z-x)}[/tex]
When x = 5 and z = 10:
[tex]\implies y=\dfrac{2(5)(10)}{(10-5)}[/tex]
[tex]\implies y=\dfrac{100}{5}[/tex]
[tex]\implies y=20[/tex]
+2+1+6 this is confusing what is the answer and explanation
Answer:
9
Step-by-step explanation:
hi I'm pretty sure this is really wrong but just kinda guessing
+2 is just a positive 2 so it's just known as 2
2+1+6 = 9
Answer: 9
Step-by-step explanation:because if its 2+1+6 then u get 2 and 6 add thats 8 then your 1 and its 9.
Identify whether each equation has one solution, infinitely many solutions, or no solution.
2.3x - 7 = -7
3x = 5 + 3x
4(10 - x) = 40 - 4x
-7 + x = - (x + 7)
Answer:
1 solution
No solution
Infinitely many solutions
1 solution
Step-by-step explanation:
2.3x - 7 = -7
2.3x = 0
x = 0
1 solution
3x = 5 + 3x
0 = 5
No solution
4(10 - x) = 40 - 4x
40 - 4x = 40 - 4x
Infinitely many solutions
-7 + x = -(x + 7)
-7 + x = -x - 7
2x = 0
x = 0
1 solution
Answer:
he is right
Step-by-step explanation:
4Gopal is paid 20 000 rupees each month.
Jamuna is paid 19 200 rupees each month
Gopal and Jamuna are both given an increase in their monthly pay.
After the increase, they are both paid the same amount each month.
Gopal was given an increase of 8%
Work out the percentage increase that Jamuna was given.
Solve for all possible values of x : |x-3|+4=1
A: 6
B: 0
C: 6 or 0
D: no real solutions
Answer:
D: no real solutions
Step-by-step explanation:
(3c-5d)²EXPAND IT PLEASE
Answer:
9c^2 - 30cd + 25d^2
Step-by-step explanation:
(3c - 5d)^2
= (3c - 5d) (3c - 5d)
= [3c * 3c] + [3c * -5d] + [-5d * 3c] + [-5d * -5d]
= 9c^2 - 30cd + 25d^2
how do you simplify 24+3x=3x+2(3•4)
Answer:
all rational numbers
Step-by-step explanation:
24+3x=3x+2(3*4) shows that there can only be two possible answer, all integers or no solution. As you can see 2*3*4 is 24, making the answer all rational numbers.