Adult Bone Marrow has stem cells that are not as "good" as embryonic ones but they still can become red blood and skin cells
The answer is 1/8.
Half-life is the time required for the amount of a sample to half its value.
To calculate this, we will use the following formulas:
1.

,
where:
<span>n - a number of half-lives
</span>x - a remained fraction of a sample
2.

where:
<span>

- half-life
</span>t - <span>total time elapsed
</span><span>n - a number of half-lives
</span>
The half-life of Sr-90 is 28.8 years.
So, we know:
t = 87.3 years
<span>

= 28.8 years
We need:
n = ?
x = ?
</span>
We could first use the second equation, to calculate n:
<span>If:

,
</span>Then:

⇒

⇒

<span>⇒ n ≈ 3
</span>
Now we can use the first equation to calculate the remained amount of the sample.
<span>

</span>⇒

⇒

<span>
</span>
Answer: 19.25 gallons
Explanation: 1 ml = 0.0011 quart
Given: 4 quarts = 1 gallon
Thus if 1 ml is equal to 0.0011 quart
70000 ml is equal to =
Now if 4 quarts is equal to 1 gallon.
77 quarts is is equal to=
I think it is e sorry if I’m wrong