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Aleks [24]
2 years ago
9

a radioactive substance has a half-life of 2 seconds. A scientist begins with a sample of 20 grams. How much of the substance re

mains after 8 seconds?
Mathematics
1 answer:
s344n2d4d5 [400]2 years ago
5 0

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.

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Which values from the set 5,7,11,13 make the inequality w 4 < 8 true
Butoxors [25]

Answer:

C

Step-by-step explanation:trust me

3 0
3 years ago
The cost of six hens and one duck at the university poultry farm is GH₵40. While four hens and three ducks cost GH₵36. What is t
Anon25 [30]

Answer:

Step-by-step explanation:

Let's call hens h and ducks d. The first algebraic equation says that 6 hens (6h) plus (+) 1 duck (1d) cost (=) 40.

The second algebraic equations says that 4 hens (4h) plus (+) 3 ducks (3d) cost (=) 36.

The system is

6h + 1d = 40

4h + 3d = 36

The best way to go about this is to solve it by substitution since we have a 1d in the first equation. We will solve that equation for d since that makes the most sense algebraically. Doing that,

1d = 40 - 6h.

Now that we know what d equals, we can sub it into the second equation where we see a d. In order,

4h + 3d = 36 becomes

4h + 3(40 - 6h) = 36 and then simplify. By substituting into the second equation we eliminated one of the variables. You can only have 1 unknown in a single equation, and now we do!

4h + 120 - 18h = 36 and

-14h = -84 so

h = 6.

That means that each hen costs $6. Since the cost of a duck is found in the bold print equation above, we will sub in a 6 for h to solve for d:

1d = 40 - 6(6) and

d = 40 - 36 so

d = 4.

That means that each duck costs $4.

3 0
3 years ago
Find the radius of a circle, when the diameter is 29 cm​
postnew [5]

Answer:

14.5cm

Step-by-step explanation:

radius is half of diameter

29 / 2 = 14.5

8 0
2 years ago
How many minutes are there in a 40 hours week?
Pavel [41]
60 minutes times 40 hours equals 2400 minutes
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Match wash hypotenuse length with the leg lengths that will create a right triangle
Ugo [173]
Hope this can help you

5 0
2 years ago
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