12 Calculate \(\sum _ { r = 3 } ^ { 6 } \frac { 12 } { r }\).
12 A sequence begins
$$\begin{array} { l l l l l l l l l l l }
1 & 3 & 5 & 3 & 1 & 3 & 5 & 3 & 1 & 3 & \ldots
\end{array}$$
and continues in this pattern.
- Find the 55th term of this sequence, showing your method.
- Find the sum of the first 55 terms of the sequence.