Answer:
9. 
10. 
Step-by-step explanation:
9. Given the sequence

In this sequence,

Note that

then the common difference in this sequence is 
You have

then the explicit formula is

10. Given the sequence

In this sequence,

Note that

then the common difference in this sequence is 
You have

then the recursive formula is

The answer to your question is 130.
Answer:
34.87% probability that all 5 have a wireless device
Step-by-step explanation:
For each student, there are only two possible outcomes. Either they own a wireless device, or they do not. The probability of a student owning a wireless device is independent from other students. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
81% of students own a wireless device.
This means that 
If 5 students are selected at random, what is the probability that all 5 have a wireless device?
This is P(X = 5) when n = 5. So


34.87% probability that all 5 have a wireless device
Here's link to the answer:
tinyurl.com/wpazsebu