Option B makes the most sense, because if you follow the steps, they fit perfectly into each other!
Let

be the n'the term of the sequence.
The first term of the sequence is

the second

is 8
the third term

is 4
the fourth term

is 2
the fifth term

is 1
We notice that:
i) the values of the terms are powers of 2, and decreasing:

ii) we also notice that the subscript integer of a, and the power of 2 at that term, add to 5.
thus the general term of the sequence is given by:

.
to fit the choices of the question, we can modify this formula as follows:

The average rate of change from n=1 to n=3 is defined as:


can be found using the general formula,

,
thus the average rate of change is (4-16)/2=-12/2=-6
Answer:

,
average rate of change=-6
Answer:
There is a
probability that the correct password is found on the sixth try.
Step-by-step explanation:
We have n passwords, only 1 is correct.
So,
Since a password is put back with other, at each try, we have that:
The probability that a password is correct is 
The probability that a password is incorrect is
.
There are 6 tries.
We want the first five to be wrong. So each one of the first five tries has a probability of
. So, for the first five tries, the probability of getting the desired outcome is
.
We want to get it right at the sixth try. The probability of sixth try being correct is
.
So, the probability that the first five tries are wrong AND the sixth is correct is:

There is a
probability that the correct password is found on the sixth try.
2.5 years required for an investment of 5000 dollars to grow to 6000 dollars at an interest rate of 7.5 percent per year, compounded quarterly.
Step-by-step explanation:
The given is,
Initial investment - $5000
Future amount - $6000
Interest rate - 7.5% (compounded quarterly)
Step:1
Formula to calculate the Future amount with compound interest,
...................................(1)
Where, F - Future amount
P - Initial amount
r - Rate of interest
n - No. of compounding in a year
t - Time period
From given,
F = $6000
P = $5000
r = 7.5%
n = 4 (compounded quarterly)
Equation (1) becomes,



Take log on both sides,

Substitute log values,
0.07918 = 4(t) (0.0080676)
= (t) (0.0322705)
= 2.45
t ≅ 2.5 years
Result:
2.5 years required for an investment of 5000 dollars to grow to 6000 dollars at an interest rate of 7.5 percent per year, compounded quarterly.
6 phone numbers are possible for one area code if the first four numbers are 202-1
<u>Solution:</u>
Given that, the first four numbers are 202-1, in that order, and the last three numbers are 1-7-8 in any order
We have to find how many phone numbers are possible for one area code.
The number of way “n” objects can be arranged is given as n!
Then, we have three places which changes, so we can change these 3 places in 3! ways

Hence 3! is found as follows:

So, we have 6 phone numbers possible for one area code.