Answer:
The number of trees at the begging of the 4-year period was 2560.
Step-by-step explanation:
Let’s say that x is number of trees at the begging of the first year, we know that for four years the number of trees were incised by 1/4 of the number of trees of the preceding year, so at the end of the first year the number of trees was
, and for the next three years we have that
Start End
Second year
-------------- 
Third year
-------------
Fourth year
--------------
So the formula to calculate the number of trees in the fourth year is
we know that all of the trees thrived and there were 6250 at the end of 4 year period, then
⇒
Therefore the number of trees at the begging of the 4-year period was 2560.
Answer:
2 x 2 x 2 x 3, so its E
Step-by-step explanation:
Answer:
2nd graph (image)
Step-by-step explanation:
The function to graph is:

It follows the general pattern of the function:
, which is general shape and in 1st and 3rd quadrants. So, we can eliminate 3rd and 4th choices (because of quadrants).
The answer is either 1st, or 2nd graph.
Now, we simply can check a point in both.
lets take x = 4, so the function would be:
f(4) = 4/4 = 1
Hence, point is:
(4,1)
The first graph doesn't go through this point. The second graph does.
hence, we can successfully choose the 2nd graph as our answer.
Answer:

So then the correct answer is B. $200.
Step-by-step explanation:
Notation
Let X be the average contribution size before John makes his contribution.
Let Y be the total contribution size before John makes his contribution.
Let Z be John's contribution.
We know that for this case $ 75 represent the original average amount before the contribution with 50% increase so we can set up the following equation in order to find the original average amount

And solvong for X we got:

Now we can find the total contribution before the donation with the following proportion:


And then with the formula of average taking in count the 6 values we can find the size of donation Z like this:



So then the correct answer is B. $200.
5/2 is a rational because this can be expressed as a ratio or fraction. 5/2 in ratio can be written as 2.5