Resistor parallel connection

Three identical resistors connected in series have a total resistance of 9 ohms. What will be their total resistance when connected in parallel

Final Answer:

R =  1 Ω

Step-by-step explanation:

$$\begin{gathered} Rs=9\Omega \\ {R}_1=R_2=R_3 \\ Rs=R_1+R_2+R_3=3\cdot R_1 \\ {R}_1=Rs/3=9/3=3\Omega \\ n=3 \\ \frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3} \\ \frac{1}{R}=\frac{3}{R_1} \\ R=R_1/n=3/3=1\Omega \end{gathered}$$

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