AMC / AIME · Arithmetic Sequences · Medium

Arithmetic Sequences: An arithmetic sequence has math terms, first term math, last term math. Find its sum.

Common differences.

Try the problem

An arithmetic sequence has

12

terms, first term

3

, last term

36

. Find its sum.

Sums.

For sums, pair first and last terms or use

S_n=\frac n2(a_1+a_n)

234