Element X is a radioactive isotope such that every 20 years, its mass
decreases by half. Given that the initial mass of a sample of Element X is 410
grams, how long would it be until the mass of the sample reached 270 grams,
to the nearest tenth of a year?

Answers

Answer 1

Answer:

12.1

Step-by-step explanation:

y=a(1/2)^t/h

270=410(1/2)^t/20

Divide both sides by 410

0.6585365854 = (1/2)^t/20

Log Both sides

Log(0.6585365854) / Log(1/2)

.6026645024= t/20

20 x .6026645024 = t

12.05329005 to the nearest tenth is 12.1 = t


Related Questions

Please help me I need an answer fast

Answers

roughly 37.5 but 37.3 should work

a knife set is on sale for $36, the set was on sale for 25% OFF. what was the original total price of the knife set?

Answers

The original price was $48

If 75% was 36, divide it by three to get 12 then multiply 12 by 4 to get 100% = 48

Leave your answers as a fraction or improper fraction.

Answers

Answer:

Soda tax — Should people have to pay an extra tax on soda or junk food?

Your conversation should include the following:

A total of at least five entries for each side (10 entries total—two to three sentences each)

Accurate facts used to support both perspectives

At least two properly cited sources used for research

Step-by-step explanation:

A car is 160 inches long. A truck is 65% longer than the car. How long is
the truck? *

Answers

Answer:

160+65%=264

Step-by-step explanation:

i think

Answer:

264 inches

Step-by-step explanation:

160/ 0.65 = 104

104 + 160 = 264

can someone please help me with this whole page asap !!!

Answers

what answers do u need

The Dubois family has $5000 set aside for an upcoming vacation in the family plans to spend 1/4 of this amount on gasoline for the drive and motel rooms along the way and 1/2 of the remainder on meals how much does the Dubois family spend on meal

Answers

Answer:

$1875

Step-by-step explanation:

Money available with Dubois family = $5000

Money to be spent on gasoline and motel room = [tex]\frac{1}{4}[/tex] of the total amount

Therefore,

Money to be spent on gasoline and motel room = [tex]\frac{1}{4} \times 5000 = \$1250[/tex]

Remaining amount of money = Total amount - Money spent on gasoline and motel room  

Remaining amount of money = $5000 - $1250 = $3750

As per question statement:

Half of the remaining money is to be spent on meals.

i.e. Money to be spent on meals = [tex]\frac{1}{2}\times \$3750 = \bold{\$1875}[/tex]

Therefore, the answer is:

$1875

15PTS PLEASE HELP ASAP!
(dont write random answers pls)
look at the pic attached:

Answers

Answer:

y=2x-1

Step-by-step explanation;

First step you have to do is get you desmos graphing calculator

input the equation- 1/2x+4 when you put it you get your line

from there you have to find one of the equations from the answer choices which one is parallel from there input your four answer choices on your graphing calculator then look which of the equations is parallel to the equation -1/2x+4 when you do that you get y=2x-1

Hope this helps :)

find the answer and when you find it you get 10 point.

Answers

Answer:

5

Step-by-step explanation:

PLEASE HELP!!!!
i need help on all of these but if you only have 1 answer that’s still great

Answers

Answer:

n = -6

x = -7

n = 27

Step-by-step explanation:

Question 1

-3n - n + 12 = 36

First we get all the variables to one side using subtraction property of equality.

-3n - n + 12 (-12) = 36 (-12)

-4n = 24

divide by the coefficient of n to isolate the variable

-4n/-4 = 24/-4

n = -6

Question 2

-2x - 3x - 15 = 20

-5x - 15 = 20

-5x = 35

x = -7

Question 3

3 + n/9 = 6

Isolate the n variable

n/9 = 6 - 3

multiply by 9

n = 27

Answer:

1. n = -6

2. x = -7

3. n = 27

what does The standard deviation mean ?

Answers

Answer:

Definition: Standard deviation is the measure of dispersion of a set of data from its mean. It measures the absolute variability of a distribution; the higher the dispersion or variability, the greater is the standard deviation and greater will be the magnitude of the deviation of the value from their mean.

Answer:

I'm on the same thing. If I'm being honest I have no idea what it is and I'm kinda freaking out bc my school stuff is due tomorrow.

Step-by-step explanation:

A recipe for pizza dough calls for 3 teaspoons of salt for every 4 cups of flour how many teaspoons of salt will be needed for 28 cups of flour.

Please show a tape diagram for this too

Answers

Its gonna be 7, im not sure how i can provide a tape diagram

Identify the transformation, and its congruence transformation?

Answers

Answer:

Reflection

Step-by-step explanation:

You only flip the triangle it doesn't rotate or slide so its Reflection

i am not sure if it is suppose to be a total of 180 degrees or 90 degrees . pls help

Answers

Answer:

the answer is c I believe

Step-by-step explanation:

5(10) 50 + 25 is 75 equals 25 and 10 + 5 is 15 so 75 + 15 is 90. so the answer is c

PLS HELP ASAP

simplify the expression that enter your answer below x + 2 x + 5 x

Answers

the answer should be 8x

Answer:

8x

Step-by-step explanation:

Combine Like Terms:

= x+2x+5x

= (x+2x+5x)

= 8x

Can someone please help me with this

Answers

Answer:

Yes

Step-by-step explanation:

Because I can assist you hit my inbox

Answer:

help you with what?

Step-by-step explanation:

post the question and I am probably 90% sure I can answer it for you I just need to know what the question is . if you've already got it done then no need to answer back .

Please helpppp !!!!!!!!!!!!! Will mark Brianliest !!!!!!!!!!!!!!!!!!!!!

Answers

Answer:

6.3

Step-by-step explanation:

7squared - 3squared

49-9= 40

square root of 40 = 6.3

Your family goes out for dinner on Sunday night. If the total bill came out to $175 but your parents had a 20% off coupon. How much will the entire meal cost if you also must pay 8% sales tax and a 18% tip?

Answers

Answer:

Step-by-step explanation:

175-20%= 35 off

175-35=140

140*8% tax= 11.20 tax

140+11.20= 151.20

151.20*18% tip= 27.216

151.20+27.22=178.42 total

What term is another word for x intercept

Answers

i think it’s an x axis

Find the circumference of the circle. Put your answer in
the box below.
Please label with inches.

Answers

Answer: 18.85 in.

Step-by-step explanation:

you take ^ divide it by 2 get three then you take three and multiple it by

pi r2

18.85 is the answer gimmi smartest plz

What is the measure of B?

Answers

44 bc c is 90 and the other is 46 , all together it would equal the area of a triangle which is 180°

what is the equation of the line through (4, -3) and (0, -2)?

Answers

Answer:y=-1/4x-2

Step-by-step explanation:

Please answer the for me

Answers

Answer:

y=-5x+30

Step-by-step explanation:

So negative 5x because you are taking five dollars out every x day so then plus 30 because since its slope intercept form y=mx+b and be is the y intercept then that should be your answer.

I NEED HELP ASAP!!! PLEASE SOMEONE HELP ME DONT SKIP!!!

Answers

Answer:

A. E = 20H

B. $380

Step-by-step explanation:

E = 20(19) since she worked 19 hrs. This equals 380

please I really need help and I cant seem to get the answer right

Answers

1 is b because...
3^2= 6
4^2= 16
10^2= 100

2 is c because...
2(2)+2= 6
2(3)+2=8
2(6)+2= 14

3 is a because...
1/2 (5)+1 = 3.5
1/2 (10)+1= 6
1/2 (20)+1= 11

A company makes steel rods shaped like cylinders. Each rod has a radius of 2 centimeters and height of 70 centimeters. How much steel will the company need to make 243 rods? Use 3.14 for pie, and round your answer to one decimal

Answers

Answer:

213,645.6cm³

Step-by-step explanation:

Area of a cylinder is expressed as;

V = πr²h

r is the radius = 2cm

h is the height = 70cm

Get the volume of one rod;

V = πr²h

V = (3.14)(2)²(70)

V = (3.14)(4)(70)

V = 879.2cm³

one steel = 879.2cm³

243 rods = x

Cross multiply;

x = 879.2 * 243

x = 213,645.6

The company will need 213,645.6cm³ volume of steel to make 243 rods

1. What is the constant rate of change between x and y in the table below?
A. -4/3 B. -3/4 C. 3/4
D. 4/3

Answers

Answer:

a

Step-by-step explanation: ya boi got at least a 90 in all classes

Answer:

D

Step-by-step explanation:

2 (k-5) + 3k = k+6
so what does k=

Answers

Answer:

Step-by-step explanation:

2(k-5)+3k=k+6k=

We move all terms to the left:

2(k-5)+3k-(k+6k)=0

We add all the numbers together, and all the variables

2(k-5)+3k-(+7k)=0

We add all the numbers together, and all the variables

3k+2(k-5)-(+7k)=0

We multiply parentheses

3k+2k-(+7k)-10=0

We get rid of parentheses

3k+2k-7k-10=0

We add all the numbers together, and all the variables

-2k-10=0

We move all terms containing k to the left, all other terms to the right

-2k=10

k=10/-2

k=-5

Not sure sorry but wish I could help

#16
Leonard is baking cookies for the
band fundraiser. He knows that he
can sell each cookie for $1.25. His
mom has also donated $25.
Altogether he expects that between
selling his cookies and the money
from his mom the band will receive
$67.50. How many cookies
did he bring to the fundraiser?

Answers

Answer:

He brought 34 cookies to the fundraiser.

Step-by-step explanation:

1.25x + 25 = 67.50

1.25x = 67.50 - 25

1.25x = 42.50

x = 42.50/1.25

x = 34

Answer:

34 cookies in total.

Step-by-step explanation:

Well if he is selling cookies for $1.25 each and has a starter of 25$, we can already mark off 25$ from $67.50. Now it's just simple division, so 42.50/1.25 is 34 cookies being sold.

Mrs. O'Brien purchases 112 ounces of laundry detergent for $13.44. Mr. O'Brien purchases a 280 ounce container of laundry detergent for $19.60. What is the difference in the unit price per ounce for the laundry detergents Mr. And Mrs. O'Brien purchase

Answers

Answer:

$0.05 per ounce

Step-by-step explanation:

Mrs. O'Brien purchases 112 ounces of laundry detergent for $13.44.

Units price = Total cost of the detergent / number of ounces

= $13.44 / 112 ounces

= $0.12 per ounce

Mr. O'Brien purchases a 280 ounce container of laundry detergent for $19.60.

Units price =Total cost of the detergent / number of ounces

= $19.60 / 280 ounces

= $0.07 per ounce

Difference in the unit price per ounce for the laundry detergents Mr. And Mrs. O'Brien purchase = $0.12 per ounce - $0.07 per ounce

= $0.05 per ounce

I’ll give Brainliest✨

Solve for w

3 - 2w + 4w = 7?

Answers

Answer:

=2

Step-by-step explanation:

Answer:

w= 2

Step-by-step explanation:

3-2w+4w=7. We move all terms to the left: 3-2w+4w-(7)=0,  Then we add all the numbers together, and all the variables: 2w-4=0. After, we move all terms containing w to the left, all other terms to the right: 2w=4, w=4/2

w=2

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