1 camera = 259
2 cameras = 259 * 2 = 518
So the total price is $518
No
There is not a common factor
The answer to your question is 13.5
The cylinder is 7.0771 centimeters tall
2018 is the 70th term of the progression.
Explanation
We start out finding the common difference of the progression:
46-17 = 29
Now we write the explicit formula for the sequence. It is of the form

We set this equal to 2018 to see if the answer is a whole number. If it is, it will be the term number that gives us 2018:
2018=17+29(n-1)
Using the distributive property,
2018=17+29*n-29*1
2018=17+29n-29
Combine like terms:
2018=29n-12
Add 12 to both sides:
2018+12=29n-12+12
2030=29n
Divide both sides by 29:
2030/29=29n/29
70=n
Since n=70, this means 2018 is the 70th term of the sequence.