8 / 200 = 4 / 100 = 0.04 ;
For my answer i got y = x - 18
Answer:
8978 grams
Step-by-step explanation:
The equation to find the half-life is:

N(t) = amount after the time <em>t</em>
= initial amount of substance
t = time
It is known that after a half-life there will be twice less of a substance than what it intially was. So, we can get a simplified equation that looks like this, in terms of half-lives.
or more simply 
= time of the half-life
We know that
= 35,912, t = 14,680, and
=7,340
Plug these into the equation:

Using a calculator we get:
N(t) = 8978
Therefore, after 14,680 years 8,978 grams of thorium will be left.
Hope this helps!! Ask questions if you need!!
The <em><u>correct answer</u></em> is:
624 crayons.
Explanation:
In 12 of the boxes, 28 crayons have not been used; this leaves 64-28=36 crayons that have been used. 12(36) = 432 crayons have been used in these boxes.
3 full boxes have been used; this is 3(64) = 192 crayons.
Together this makes 432+192 = 624 crayons that have been used.