ARITHMETIC SERIES

An expression denoting the sum of the terms of an arithmetic sequence.

• Arithmetic Mean

• Arithmetic Series

• Geometric Sequence

Which of the following are used to solve arithmetic series?

•  $a_n=\ a_1+\left(n-1\right)d$  

•  $S_n=\frac{n}{2}\left(a_1+a_n\right)$  

•  $S_n=\frac{n}{2}\left[2a_1+\left(n-1\right)d\right]$  

Simplify: 3+10+17+24+31+38+45

Find the sum of the first 12 terms of the arithmetic sequence 2, 5, 8,...

A pile of soft drink bottle caps has 1 cap on the top layer, 2 caps on the next layer, 3 caps on the next layer, and so on. How many caps are there in the pile if it contains 26 layers?