Do you know that you have to own at least 10 acres in order to build a home in the countryside?
In-taking new substances and excreting waste
Answer:
3.9 billion years
Explanation:
The half-life of potassium-40 is the time it takes for half of it to decay.
After one half-life, half of the original amount will remain.
After a second half-life, half of that amount will remain, and so on.
We can construct a table as follows:

We see that the mass will drop to 10 g after three half-lives.
1 half-life = 1.3 billion years
3 half-lives = 3.9 billion years
<span>In DNA adenine (A) pairs with thymine (T) & cytosine (C) with guanine (G), so if 28% is guanine, then there is also 28% of C, totaling 56%. This leaves 44% which must be split evenly between A and T, so there is 22% thymine (as well as 22% adenine)</span>