<span>The answer is B. 498</span><span>
</span>
An arithmetic sequence is an ordered list of numbers where the next number is found by adding on to the last number (ex: 2,5,8,11... is a sequence where 3 is added on to find the next number).
The equation for an arithmetic sequence is
![A_{n} =A_{1} + (n-1)d](https://tex.z-dn.net/?f=A_%7Bn%7D%20%3DA_%7B1%7D%20%2B%20%28n-1%29d)
![A_{n}](https://tex.z-dn.net/?f=A_%7Bn%7D)
is the "n-th" number in the sequence (ex:
![A_{1}](https://tex.z-dn.net/?f=A_%7B1%7D)
is the first term in the sequence)
d is the number you add (common difference) to find the next number
The first number in the sequence is 3 so
![A_{1} =3](https://tex.z-dn.net/?f=A_%7B1%7D%20%3D3)
8-3=5 , 13-8=5 , and 18-13=5 so d=5 (add 5 to get the next number)
![A_{n}=A_{1}+(n-1)d](https://tex.z-dn.net/?f=A_%7Bn%7D%3DA_%7B1%7D%2B%28n-1%29d)
![A_{100}=3+(100-1)(5)](https://tex.z-dn.net/?f=A_%7B100%7D%3D3%2B%28100-1%29%285%29)
<span>
![A_{100}=3+(99)(5)](https://tex.z-dn.net/?f=A_%7B100%7D%3D3%2B%2899%29%285%29)
</span><span>
![A_{100}=3+495](https://tex.z-dn.net/?f=A_%7B100%7D%3D3%2B495)
</span><span>
![A_{100}=498](https://tex.z-dn.net/?f=A_%7B100%7D%3D498)
</span>
The answer is B. 498