Answer:
D. 
Step-by-step explanation:
let's call A the number of copies sold of newspaper A and B the number of copies sold of newspaper B.
So, we can formulate the following equations from the sentence: a certain store sold copies of 256 Newspaper A for $1.00 each and copies of Newspaper B for $1.25 each as:
A + B = 256 (1)
1A + 1.25 B = Total Revenue (2)
Then, r and p are equal to:
(3)
(4)
Isolating A from (4) and B from (1), we get:
(5)
(6)
Finally, replacing (5) and (6) in (3), we get:
This is an exponential growth/decay problem. It has a formula, and it doesn't matter which you have...the formula is the same for both, except for the fact that you're rate is decreasing instead of increasing so you will use a negative rate. The formula is this: A = Pe^rt, where A is the ending amount, P is the beginning amount, e is euler's number, r is the rate at which something is growing or dying, and t is the time in years. Our particular formula will look like this: A = 2280e^(-.30*3), Notice we have a negative number in for the rate (and of course it's expressed as a decimal!). First simplify the exponents: -.30*3 = -.9. On your calculator you have a 2nd button and a LN button. When you hit 2nd-->LN you have "e^( " on your display. Enter in -.9 and hit enter. That should give you a display of .4065695. Now multiply that by 2280 to get 926.98, the value of the computer after it depreciates for 3 years at a rate of 30% per year.
Answer:
d
Step-by-step explanation:
Radius is always gonna be half of what the diameter is
