What is the equivalent resistance of series combination of 3 resistors?
\( R_{S=} R_{1+} R_2+R_3\)
\( R_s=\frac{1}{R_1}+\frac{1}{R_2} +\frac{1}{R_S }\)
\( R_{s=} \frac{(R_{1+} R_2)}{R_3 }\)
\( R_{s=} \frac{1}{(R_{1+} R_{2+} R_s)}\)
