Suppose a laboratory has a 30 g sample of polonium-210. The half-life of polonium-210 is about 138 days. a. How many half-lives of polonium-210 occur in 1104 days? b. How much polonium is in the sample 1104 days later?

9; 0.06 g
8; 0.12 g
8; 2,070 g
8; 3.75 g

Answers

Answer 1

Step-by-step explanation:

the decay or "half-life" of radioactive particles is really a big joke by nature, in my opinion.

it takes that much time for half of the amount to decay, so, naturally, one wound assume that after a second interval then the other half is gone.

but far from it. no, only the half of the originally remaining half is then gone (the half of a half is 1/2 × 1/2 = 1/4). and after another interval the half of the half of the half is then gone. and so on.

so, this creates a geometric sequence with the common factor (or ratio) if 1/2.

that means every term is created by multiplying the previous term by 1/2.

a.

how many "half-lives" in 1104 days ?

well, with every 138 days such a half-life is over.

so, the answer is how often 138 fits into 1104 :

1104 / 138 = 8

there are 8 "half-lives" of polonium-210 in 1104 days.

b.

how much polonium-210 is in the sample after 1104 days ?

since we have 8 half-lives, we need to multiply the original amount 8 times by 1/2. in other words by 1/2⁸.

2⁸ = 256

so, our calculation is

30 g × 1/256 = 0.1171875 g ≈ 0.12 g

so, the second answer option is correct.


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the answer would be 2!

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Answer:

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Step-by-step explanation:

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Answers

Answer:

A survey shows that the probability that an employee gets placed in a suitable job is 0.65. So, the probability he is in the wrong job is 0.35.The test has an accuracy rate of 70%. So, the probability that the test is inaccurate is 0.3. Thus, the probability that someone is in the right job and the test predicts it wrong is The probability that someone is in the wrong job and the test is right is 

Mr Wong spent $3750 on general expenses last month 20% of his general expenses
was electrioty charges. How much money did he pay for electricity charges laat
month?

Answers

Answer:

$750

Step-by-step explanation:

20% can also be written as 1/5 in fraction form (20/100)

3750 x 1/5 = 750

Two angles are complementary (the sum of the two angles is 90°). The sum of the first
angle plus twice the second angle is 128°. Find the measures of the angles.

Answers

Answer:

A = 52º AND B=38º

Step-by-step explanation:

Let's call A and B the two angles.

First condition: A + B = 90º

Second cond: A + 2B = 128º

Subtract the first condition to the second: B = 38º

Replace the value of B in any of the 2 conditions; e.g. in the first.

A + 38º = 90º

A = 90º - 38º = 52º

hromosome 13 in the human body contains a DNA molecule that is about 3.19 centimeters long.

What is the combined length of 102 of these molecules?

Answers

Answer:3,190 centimeters

Step-by-step explanation:

math is easy

During a basketball game a player makes 12 of 18 free throws attempted. Write the ratio as a fraction reduced to lowest terms

Answers

Answer:

[tex]\frac{2}{3}[/tex]

Step-by-step explanation:

12 out of 18 free throws is also equal to the fraction [tex]\frac{12}{18}[/tex]. To simplify this fraction, we have to find out the greatest common factor (GCF) of 12 and 18. It turns out that the GCF of 12 and 18 is 6. So, we have to divide the fraction by 6 to reduce it to its lowest terms.

[tex]\frac{12}{18} /\frac{6}{6} =\frac{2}{3}[/tex]

I hope this helps! Have a lovely day!! :)

which expression is equivalent to (x^9yz^4)^5

Answers

Applying the rule of exponent, the equivalent expression is: [tex]x^{45}y^{5}z^{20}[/tex]

What is the Rule of Exponents?

One of the rules of exponents is given as, [tex](xy)^m=(x^m)(y^m)[/tex].

Therefore, given:

(x9yz4)5

To find the equivalent expression, apply the rule of exponents as shown below:

[tex](x^9yz^4)^5=(x^{9*5})(y^5)(z^{4*5})[/tex]

[tex](x^9yz^4)^5=x^{45}y^5z^{20}[/tex]

Therefore, applying the rule of exponent, the equivalent expression is:

[tex]x^{45}y^{5}z^{20}[/tex]

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Will give points please help

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Answer:

Part A

Step-by-step explanation:

Did test for flvs, brainliest please ;)

What is the volume of this container?

Answers

Answer:

6000 cm^3

Step-by-step explanation:

2(10 * 20 * 15) = 6000

What is the answer?

2/5 + 3/4​

Answers

2/5+3/4

Take LCM

5×4=20

Now

2/5+3/48+15/2023/20

Answer:

23/20

Step-by-step explanation:

2/5 + 3/4

LCM = 5 * 4 = 20

=》2/5 * 4/4 = 8/20

=》3/4 * 5/5 = 15/20

So,

2/5 + 3/4

= 8/20 + 15/20

= 23/20

_________

Hope it helps ⚜

sorry for not putting the picture

Answers

Answer:

Answer bellow

Step-by-step explanation:

9cm⋅12cm=108cm²

17cm=108cm²

7cm=108cm²

9cm=108cm²

3cm=108cm²

Answer:

407

Step-by-step explanation:

9 x 17 = 153

9 x 16 = 135

(15 x 14) x 1/2 = 105

add em up...

153 + 135 + 105 = 407

Hope this helps! Please let me know if you need more help or think my answer is incorrect. Brainliest would be MUCH appreciated. Also remember to rate answers to help other students, While leaving thanks to answers that help you. Have a great day!

The area of a rectangle is 27x2+27x-30 square feet. The length of the rectangle is 9x– 6 feet. What is the width of the rectangle?

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Divide the polynomials to get the 3x + 5

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Domain of this function is R or (-∞,∞)

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Find the surface area of the cone in terms of π.

Answers

Answer:

161 × pi cm²

Step-by-step explanation:

we just had the question about the lateral surface area (which is the area of the "mantle" of the cone from the round bottom to the pointy top).

the whole surface area of a cone is then simply the lateral surface area plus the ground area, which is a circle.

so, we have

A = pi×r×sh + pi×r²

r = radius (remember, this is half of the diameter)

sh = slant height (the length of the "mantle" straight up from the ground to the top)

so, the surface area of our cone here is

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Product of 630 and 7.2X 10 to the 4th power

Answers

Put it into your calculator

Product means multiply [tex]\times[/tex]

4th power means [tex]10^4[/tex]

[tex]630\ \times\ 7.2\times10^4 = 45360000 = 4.536\times10^7[/tex]

Full question and options​

Answers

Answer:

D

Step-by-step explanation:

A triangle is always determined by the names of its angles. If, for any reason, you wanted to label it by its side names(which I don't even think you can do but assuming you wanted to), you dont even have the names for all three sides here. So, it can only be d. A, X, and T are the three angle names for this triangle, so this is triangle ATX or AXT.

Answer:

ATX (option d)

Step-by-step explanation:

Sides of any polygon are called as vertices.

Vertices of the triangle or endpoints of the sides of the polygon are A, T and X.

Triangles can also be classified by their angles. In an acute triangle all three angles are acute.

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So first in a separate sheet of paper you have to look for how many members of fam and friends does Kimberly have. Then write down the amount of money she has in total.
Then subtract 120-36 cause she buys the book.
Which equals. 84
Then you have to subtract 84 from what I said at the beginning

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Answer:

Hope the picture will help you. And Please Mark me brilliant!!!

Write the following expression in terms of logs of x,y and z
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Answers

We can write the log expression in terms of the log of x, y, and z as expression 1/2(logx+2logy-8logz).

What is a logarithm?

It is another way to represent the power of numbers and we say that 'b' is the logarithm of 'c' with base 'a' if and only if 'a' to the power 'b' equals 'c'.

[tex]\rm a^b = c\\\\log_ac = b[/tex]

We have an expression in logarithm:

[tex]=\rm log\sqrt{\frac{xy^2}{Z^8} }\\\\=log(\frac{xy^2}{Z^8})^{\frac{1}{2} }\\\\=\frac{1}{2}log(\frac{xy^2}{Z^8})[/tex]                         [tex](\rm loga^b = (b)log(a))[/tex]

[tex]\rm\frac{1}{2} (log(xy^2)-logz^8)[/tex]              [tex](\rm log(\frac{a}{b} )= loga - logb)[/tex]

[tex]\rm\frac{1}{2} (log(x)+log(y^2)-logz^8)[/tex]   [tex](\rm logab = loga+logb)[/tex]

[tex]\rm\frac{1}{2} (log(x)+2log(y)-8logz)[/tex]

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Dawn can paint of a wall in 1 hour. How
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Dawn can paint 2 walls in two hours according to ur question

The mean for the data in the dot plot is 5. What is the absolute deviation for the data point at 7?

Answers

Answer:

The answer is 2. Hope this helps!

Step-by-step explanation:

Answer:

2

Step-by-step explanation:

Rob and Mike are selling cookie dough
for a school fundraiser. Customers can
buy packages of white chocolate chip
cookie dough and packages of oatmeal
cookie dough. Rob sold 12 packages of
white chocolate chip cookie dough and
6 packages of oatmeal cookie dough for
a total of $192. Mike sold 6 packages of
white chocolate chip cookie dough and
12 packages of oatmeal cookie dough
for a total $222. What is the cost of one
package of white chocolate chip cookie
dough and one package of oatmeal
cookie dough?

Answers

The cost of one package of white chocolate chip cookie is $9 while the cost of one package of oatmeal cookie dough is $14.

What is an equation?

An equation is an expression used to show the relationship between two or more numbers and variables.

Let x represent the cost of white chocolate chip and y represent the cost of oatmeal dough, hence:

12x + 6y = 192   (1)

Also:

6x + 12y = 222    (2)

From both equations:

x = 9, y = 14

The cost of one package of white chocolate chip cookie is $9 while the cost of one package of oatmeal cookie dough is $14.

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is (x-4) a factor of f(x)=x^3-2x^2+5x+1 explain your reasoning

Answers

Answer:

No.

Step-by-step explanation:

It's simpler than you might expect.

If [tex](x - 4)[/tex]  is a factor, then it means that it the function [tex]f(x) = x^3 - 2x^2 + 5x + 1[/tex] can have [tex](x - 4)[/tex] factorised out.

This means that we can say [tex](x - 4) = 0[/tex]

Therefore [tex]x = 4[/tex]

If we put [tex]x = 4[/tex] into the equation:

[tex]f(4) = (4)^3 - 2(4)^2 + 5(4) + 1\\= 64 - 32 + 20 + 1\\= 53[/tex]

We didn't get 0, therefore it isn't a factor!

{( - 1, 2), (0, 3), (1, 4)}
Which algebraic equation gives the correct rule for the table?

Answers

Answer:

The rule for the input-output table below is: add 1.5 to each input number to find its corresponding output number. Use this rule to find the corresponding output numbers. To find each output number, add 1.5 to each input number. Then, write that output number in the table.

-10.3r = 1.03 what is R?

Answers

Answer:

r= -0.1

Step-by-step explanation:

the correct answer is r=0.1

Find the surface area of the prism.

Answers

[tex]s \: a \: = (2 \times \frac{1}{2} \times 4 \times 6) + (3 \times 2 \times 5) \\ [/tex]

[tex]s \: a \: = 24 + 30[/tex]

[tex]s \: a \: = 54 \: \: {yd}^{2} [/tex]

Amelia is conducting a survey in their neighborhood about noise pollution.

Choose three things they should do to get a representative sample and check that it is representative.

Answers

Amelia should randomly choose people only in their block.

Amelia should ask people what part of the neighborhood they live in.

Amelia should ask people their age.

What is representative sample?

A representative sample are data collected from small group of individual which can be use to represent a large population of people so as to reach a conclusion.

Most researcher tend to make use of representative sample when they want to draw a conclusion as it save time and reduce the stress of having to carryout survey on a larger population.

Therefore Amelia should randomly choose people only in their block.

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Answer:

heres what i got!

It takes 4 people 6 days to build a wall. How long would it take 6 people to build the same wall?

Answers

Answer:

1 day

Step-by-step explanation:

4=6

2=3

2*3=6

so 3/3=1

It would take 6 people to build the wall 1 day

It takes 4 days to build the same wall with 6 people based on the given ratio.

What are the ratio and proportion?

The ratio is the division of the two numbers.

Proportion is the relation of a variable with another. It could be direct or inverse.

As per the given,

It takes 4 people 6 days to build a wall.

The number of people days taken = 4 x 6 = 24 people takes

This means if one person wants to build them it takes 24 days.

For 6 people the time taken will be 24/6 = 4 days.

Hence "It takes 4 days to build the same wall with 6 people based on the given ratio".

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Adam says 0.25 is smaller then 2
_
5
Explain why he is correct

Answers

Step-by-step explanation:

0.25 = 1/4 is not reach to 1

2 is an integral number.

So, 0.25 is smaller than 2

Answer:

2/5 is equal to 0.40, which is higher than 0.25

Step-by-step explanation:

2 ÷ 5= 0.4 which is the same as 0.40

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