Answer:
There were 210 downloads of the standard version.
Step-by-step explanation:
This question can be solved using a system of equations.
I am going to say that:
x is the number of downloads of the standard version.
y is the number of downloads of the high-quality version.
The size of the standard version is 2.6 megabytes (MB). The size of the high-quality version is 4.2 MB. The total size downloaded for the two versions was 4074 MB.
This means that:

Yesterday, the high-quality version was downloaded four times as often as the standard version.
This means that 
How many downloads of the standard version were there?
This is x.

Since 




There were 210 downloads of the standard version.
Here's your answer to the first problem
Answer:
A = 50.26 sq meters
Step-by-step explanation:
we have to find the diameter first by using the circumference:
C = πd
25.12 = πd
25.12/π = d
8 = d
this means the radius is 4
A = πr²
A = π4² or 16π
A = 50.26 sq meters
A: To find the rate in feet per minute, we can use the information given.
Every two minutes, the submarine dives 300 feet. So

.
In order to confirm that our rate is correct, we can use the second set of information given.

=

.
Since we know that the rate is 150 feet per minute, we can multiply it by any number of minutes and get the answer of how deep the submarine is. We can use a variable x to represent the number of minutes and y to represent the depth in feet.

There's our equation.
B: It would be more reasonable to use an equation with the rate feet per minute because it is more accurate since the time interval isn't too big.