Step 1: Formula for resistance in series.
When resistances are connected in series, the total resistance \( R_{\text{total}} \) is the sum of the individual resistances:
\[
R_{\text{total}} = R_1 + R_2 + R_3
\]
where \( R_1, R_2, \) and \( R_3 \) are the resistances of the individual resistors. Step 2: Conclusion.
Thus, the total resistance in a series circuit is the sum of the individual resistances.