Answer:
4 packages
Step-by-step explanation:
If there are 20 and stickers are sold in 15 sheets, then you got to work backwards. take the answer and multiply it by the amount of sheets. For example: 4 times 15 is 60, 60 divided by 20 is 3. No leftover numbers.
Answer:

Step-by-step explanation:
<em>Hey there!</em>
Well to add this we need to pu it in improper form.
7/5 + 23/4
Now we need to find the LCM.
5 - 5, 10, 15, 20, 25, 30
4 - 4, 8, 12, 16, 20, 24, 28
So the LCD is 20.
Now we need to change the 5 and 4 to 20.
5*4 = 20
7*4 = 28
<u>28/20</u>
4*5=20
23*5=115
<u>115/20</u>
Now we can add 28 and 115,
= 143/20
Simplified
7 3/20
<em>Hope this helps :)</em>
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!!